Citation Nr: 21010850 Decision Date: 02/25/21 Archive Date: 02/25/21 DOCKET NO. 15-14 789A DATE: February 25, 2021 ORDER Entitlement to service connection for a cardiovascular disability, to include aortic stenosis, coronary artery disease (CAD) and/or hypertension, to include as due to exposure to ionizing radiation is denied. FINDING OF FACT The Veteran’s cardiovascular disability, to include aortic stenosis, CAD and/or hypertension is not shown to be related to any disease, injury, or incident during service, to include exposure to ionizing radiation; nor was any such disease shown within the first post service year. CONCLUSION OF LAW The criteria for entitlement to service connection for cardiovascular disability, to include aortic stenosis, CAD and/or hypertension, have not been met. 38 U.S.C. §§ 1101, 1112, 1113, 1131, 1137; 38 C.F.R. §§ 3.303, 3.307, 3.309, 3.311. REASONS AND BASES FOR FINDING AND CONCLUSION The Veteran served on active duty from April 1957 to December 1960. This matter comes before the Board of Veterans’ Appeals (Board) on appeal from a January 2013 rating decision by the Department of Veterans Affairs (VA) Regional Office (RO) in Newark, New Jersey. In September 2017, the Board remanded the matter to the Agency of Original Jurisdiction (AOJ) for additional development. The matter has been returned to the Board for appellate review. Service Connection Service connection may be established for disability resulting from personal injury suffered or disease contracted in the line of duty in the active military, naval, or air service or for aggravation of a preexisting injury suffered or disease contracted in line of duty. 38 U.S.C. § 1110 (wartime), 1131 (peacetime). In general, to establish a right to compensation for a present disability, a Veteran must show: (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service - the so-called “nexus” requirement. Holton v. Shinseki, 557 F.3d 1362, 1366 (Fed. Cir. 2009). Service connection may be granted for any disease initially diagnosed after service when all of the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303 (d). Certain chronic diseases such as arteriosclerosis and cardiovascular-renal disease to include hypertension, will be presumed related to service if they were noted as chronic in service; or, if they manifested to a compensable degree within a presumptive period following separation from service; or, if continuity of the same symptomatology has existed since service, with no intervening cause. 38 U.S.C. §§ 1101, 1112, 1113, 1137; Walker v. Shinseki, 708 F.3d 1331, 1338 (Fed. Cir. 2012); Fountain v. McDonald, 27 Vet. App. 258 (2015); 38 C.F.R. §§ 3.303 (b), 3.307, 3.309(a). Service connection for disability that is claimed to be attributable to exposure to ionizing radiation during service can be demonstrated by different methods. See 38 U.S.C. § 1112 (c); 38 C.F.R. § 3.309 (d); Davis v. Brown, 10 Vet. App. 209, 211 (1997); Rucker v. Brown, 10 Vet. App. 67, 71 (1997). First, there are certain types of cancer that are presumptively service connected, specific to radiation-exposed veterans. 38 U.S.C. § 1112 (c); 38 C.F.R. § 3.309 (d). Second, when a "radiogenic disease" first becomes manifest after service, and it is contended that the disease resulted from exposure to ionizing radiation during service, various development procedures must be undertaken in order to establish whether or not the disease developed as a result of exposure to ionizing radiation. 38 C.F.R. § 3.311 (a)(1). Third, even if the claimed disability is not listed as a presumptive disease under 38 C.F.R. § 3.309 (d) or as a radiogenic disease under 38 C.F.R. § 3.311, service connection must still be considered under 38 C.F.R. § 3.303 (d) in order to determine whether the disease diagnosed after discharge was incurred during active service. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). A claimant is entitled to the benefit of the doubt when there is an approximate balance of positive and negative evidence. See 38 C.F.R. § 3.102. The preponderance of the evidence must be against the claim for benefits to be denied. See Alemany v. Brown, 9 Vet. App. 518 (1996) Entitlement to service connection for a cardiovascular disability, to include aortic stenosis, CAD and/or hypertension, to include as due to exposure to ionizing radiation, is denied. The Veteran maintains entitlement to service connection for a cardiovascular disability due to exposure to ionizing radiation during his naval service. It is not in dispute that he was exposed to ionizing radiation; the Defense Threat Reduction Agency (DTRA) confirmed the Veteran as a participant of Operation HARDTACK I, a U.S. atmospheric nuclear test series conducted at the Pacific Proving Ground in 1958. Indeed, service connection has been granted for residuals of basal cell carcinoma and bladder cancer presumptively due to radiation/atmospheric exposure in accordance with 38 C.F.R. § 3.311. The current cardiovascular disease was not shown during the Veteran's active service and the record reflects he initially underwent coronary artery bypass grafting of 2 vessels in 1982, with aortic valve replacement in 2008. Hypertension was not noted prior to that time. See VA treatment records. It is not argued or shown in the record that the cardiovascular disease was present in service, or that the presumptive-type of cardiovascular disease was present within a year of service separation, or for decades following service. More specifically, when examined in October 1959 and December 1960, the heart and vascular system were normal. Blood pressure was 130/80 and 114/80, respectively. Rather, the crux of this matter is whether the current cardiovascular disease is related to the documented atmospheric radiation exposure. For the following reasons, the preponderance of the evidence is against the claim. As noted above, service connection for disorders claimed as due to exposure to ionizing radiation may be established in three different ways: (a) for radiation-exposed Veterans, on a presumptive basis; (b) for radiogenic disease, on a direct basis after specified development procedures are conducted, or; (c) on a direct basis by showing that the disease was incurred during or aggravated by service. With respect to the first of the above-described methods of establishing service connection, "radiation-exposed Veteran" means a Veteran who participated in a "radiation-risk activity." 38 U.S.C. § 1112(c)(3)(A); 38 C.F.R. § 3.309(d)(3)(i). "Radiation-risk activity" includes onsite participation at atmospheric nuclear tests. Id. The term "onsite participation" includes presence at a test site or test staging area to perform official military duties in connection with completion of projects related to the nuclear test during the six-month period following the official operational period of the atmospheric nuclear test. Id. The operational period for Operation HARDTACK I extended from April 28, 1958 to October 31, 1958. In the instant case, the Veteran was involved in Operation HARDTACK I activities as noted. He was aboard the USS Perkins (DDR877) during Operation Hardtack I at Enewetak and at Bikini Atoll in the Pacific. A memorandum issued by the Defense Threat Reduction Agency (DTRA) in March 2015 confirms his participation. Therefore, the Veteran meets the criteria for a “radiation exposed Veteran.” However, the diseases specific to radiation-exposed veterans do not include any cardiovascular disability, to include aortic stenosis, CAD and/or hypertension with which the Veteran has been diagnosed. Thus, service connection is not warranted on such a presumptive basis. Under the second method, a "radiogenic disease" may be service-connected if warranted after specified developmental procedures have been conducted under the framework of 38 C.F.R. § 3.311. The regulation states that if the Veteran has one of the enumerated radiogenic diseases, a radiation dose assessment will be obtained and the case will be referred to the Under Secretary for Benefits for review as to whether sound scientific medical evidence supports the conclusion that it is at least as likely as not that the Veteran's disease resulted from radiation exposure during service. Pursuant to 38 C.F.R. § 3.311, a "radiogenic disease" is a disease that may be induced by ionizing radiation, and specifically includes all forms of cancer. Notably, this regulation does not include any non-cancerous heart conditions. 38 C.F.R. § 3.311 (b)(2). However, if a claim is based on a disease other than one of the listed conditions, VA shall nevertheless consider the claim under this section provided that the claimant has cited or submitted competent scientific or medical evidence that the claimed condition is a radiogenic disease. 38 C.F.R. § 3.311 (b)(4). Initially, 38 C.F.R. § 3.311 (a) discusses the circumstances when it is necessary to obtain a dose assessment of the size and nature of radiation dose or doses. In this case, of record is a December 2011 letter from the Defense Threat Reduction Agency (which was obtained as part of a separate earlier claim) that provided a dose assessment. The Veteran and his representative have at various times brought up issues with the dose estimate, but the Board does not find that there is any other dose estimate from another credible source that precludes acceptance of the dose estimate obtained in this case. Here we note the article referenced by the Veteran, Estimation of Radiation Doses of US Military Test Participants of Nuclear Testing: A Comparison of Historical Film Badge Measurements, Dose Reconstruction and Retrospective Biodosimetry, published in February 2019. But there is no conclusion in this article that the dose estimate used in this case is actually faulty. Also, the argument submitted by the Veteran’s representative, that obtaining an alternate dose estimate should be considered, does not persuade the Board that the dose estimate is not appropriate. No alternative dose estimate is provided. The Veteran contends, essentially that the DTRA dose estimate is low. He argued that his duties around the ship resulted in much higher levels. VA may also consider a dose estimate from a “credible source” submitted by or on behalf of a Veteran. A dose estimate shall be considered from a “credible source” if prepared by a person or persons certified by an appropriate professional body in the field of health physics, nuclear medicine or radiology and if based on analysis of the facts and circumstances of the particular claim. 38 C.F.R. § 3.311 (a)(3). Ultimately, he has not provided any alternate dose estimate or credible and competent argument that the DTRA estimate, noted to be actually higher than the actual dose he received should not be used. The DTRA dose estimate was the following: Doses which the veteran could have received during participation in US atmospheric nuclear testing are not more than: -External gamma dose: 18 rem -External neutron dose: 0 5 rem -Total skin dose to any skin area (beta plus gamma): 550 rem Next, 38C.F.R. §3.311(b)(1) provides that: When it is determined: (i) A veteran was exposed to ionizing radiation as a result of participation in the atmospheric testing of nuclear weapons...; (ii) (ii) The veteran subsequently developed a radiogenic disease; and (iii) (iii) Such disease first became manifest within the period specified in paragraph (b)(5) of this section; before its adjudication the claim will be referred to the Under Secretary for Benefits for further consideration in accordance with paragraph (c) of this section. As to the requirement in item (i), the evidence of record indicated that the Veteran was exposed to ionizing radiation as a result of participation in the atmospheric testing of nuclear weapons. See e.g., December 2011 Defense Threat Reduction Agency Letter (stating that the Veteran is “a confirmed participant of U.S. atmospheric nuclear testing” and providing a dose assessment). Next as to the requirement in item (ii), 38 C.F.R. § 3.311 (b)(2) states that “[f]or purposes of this section the term ‘radiogenic disease’ means a disease that may be induced by ionizing radiation and shall include the following,” followed by various specifically listed diseases, which do not include the cardiovascular disabilities at issue here (aortic stenosis, CAD and/or hypertension). 38 C.F.R. § 3.311 (b)(4), however, states that: If a claim is based on a disease other than one of those listed in paragraph (b)(2) of this section, VA shall nevertheless consider the claim under the provisions of this section provided that the claimant has cited or submitted competent scientific or medical evidence that the claimed condition is a radiogenic disease. In this case, the Veteran and his representative have cited and submitted scientific or medical evidence that some of the claimed cardiovascular disabilities at issue maybe radiogenic diseases. In this regard, of record is a February 2013 opinion from private Dr. M.A., a cardiologist, who stated that “[i]t is my opinion that it is at least likely as not that the nuclear radiation [the Veteran] was exposed contributed to his aortic valve stenosis.” The opinion is written on a prescription form. In August 2017 the Veteran cited an October 2011 article from the National Institute of Health that was titled “Radiation as a Risk Factor for Cardiovascular Disease.” The representative stated that “[a]ccording to that article, radiation can place individuals at an increased risk of developing cardiovascular disease.” Also, as noted above, the Veteran in a May 2015 statement referenced (and submitted) an article (titled “Radiation Induced Cardiac Valve Disease in a Man From Chernobyl”) that he stated “states that significant [CAD] can be expected with radiation exposure.” Based on the evidence of record, the Veteran’s claim is for a disability that is a radiogenic disease within the meaning of 38 C.F.R. § 3.311. In addition, the Board notes that a negative VA opinion was obtained in May 2015 as to direct service connection (the third way to substantiate a claim for entitlement to service connection based on exposure to ionizing radiation). This opinion focused on aortic valve stenosis. The Board has recharacterized the scope of the Veteran’s claim to include CAD and hypertension. In addition, the Veteran (and his representative) submitted additional evidence and argument in response to the May 2015 VA opinion, to include highlighting inaccurate statements contained in the opinion in relation to a prior heart surgery/hospitalization and medication taken. See August 2017 Veteran Statements (two), August 2017 Representative Written Brief Presentation. In September 2017, the Board remanded the claim for referral to the Under Secretary for Benefits in accordance with 38 C.F.R. § 3.311(c). The Board noted that 38 C.F.R. § 3.311(c) provides that “the Under Secretary for Benefits...may request an advisory medical opinion from the Under Secretary for Health.” On remand, the AOJ obtained Dr. A.’s records and other updated treatment records. Thereafter, it requested administrative review to the Under Secretary for Benefits in accordance with 38 C.F.R. § 3.311. In September 2020, the Director, Compensation Service, requested Radiation Review under 38 C.F.R. § 3.311 from the Under Secretary for Health. The response was received in October 2020. The response was prepared by a VA Health Physicist and reviewed by the Director, a medical doctor. It was from the Director, Post-9/11 Era Environmental Health Service. The detailed response is comprehensive and is reported in detail for accuracy: 1. This is in response to your memorandum of September 25, 2020 and the Board of Veterans Appeals remand, dated September 21, 2017. 2. The Veteran, born March [X] had honorable active military service in the U.S. Navy from April 28, 1957 to December 18, 1960. The Veteran claimed service-connection for a cardiovascular disability, to include aortic stenosis, coronary artery disease (CAD) and/or hypertension as a result of exposure to ionizing radiation during service while aboard the USS Perkins (DDR877) during Operation Hardtack I at Enewetak and at Bikini Atoll in the Pacific. He reported witnessing eight nuclear tests and stated their mission was to act as a weather ship and to ensure no unauthorized ships entered the fallout area The Veteran reported he was the aerology officer, responsible for overseeing the release of weather balloons and tracking them by radar to determine wind velocity and direction. He was also the ships navigator, keeping the Captain advised of their location. The Veteran stated that during one shot, he had opened the watertight door on the ship and stepped out on the deck. Once he realized a nuclear device had been set off, he quickly went back in. The Veteran reported that on occasion, after a shot, the ship’s crew was given liberty on Bikini for recreation, including swimming and walking around in shorts (though they were told not to eat the fish or coconuts). On March 26, 2015, the Defense Threat Reduction Agency (DTRA) confirmed the Veteran as a participant of Operation HARDTACK I, a U.S. atmospheric nuclear test series conducted at the Pacific Proving Ground in 1958. In the preceding response of December 9, 2011, DTRA stated the doses for which the Veteran could have received during participation in U.S. atmospheric nuclear testing are not more than: External gamma dose: 18 rem External neutron dose: 0.5 rem Total skin dose to any skin area (beta plus gamma): 550 rem The Veteran’s service treatment records contain DD Form 1141, Record of Exposure to Ionizing Radiation, for the period of April 6, 1958 to May 22, 1958. The form shows gamma radiation measured by film badge with an accumulative total dose of 0105 mr (0.105 rem). We will not add this measured dose to the DTRA estimate. The estimate accounts for all measured doses and adds a considerable factor, which benefits the Veteran with a much higher dose. 3. The Veteran reported that in June 1982, he underwent a three-vessel coronary artery bypass graft (CABG). Medical records from November 2008 show a diagnosis of coronary artery disease and aortic stenosis, for which the Veteran had an aortic valve replacement. The records also show the Veteran had hypertension. The Veteran’s cardiovascular disability was reported approximately twenty-four years after exposure to ionizing radiation. The Veteran was 26 years old at the time of exposure. Records show the Veteran is a Caucasian male and a nonsmoker. He reported no family history of cancer. His records show that his mother had a history of heart disease, hyperlipidemia, and hypertension. The Veteran is a retired engineer. No post-service exposure to radiation was noted or reported. A cardiovascular disability, to include aortic stenosis, CAD, and/or hypertension is not a disease listed under 38 C.F.R. § 3.309(d). The Veteran submitted an article titled “Radiation induced cardiac valve disease in a man from Chernobyl” to support his contention that aortic valve stenosis can be caused by exposure to nuclear radiation. He also submitted an article from the Mayo Clinic on aortic valve stenosis to support his contention that radiation may damage the aortic valve and eventually lead to aortic stenosis. In addition, reference was made to an October 2011 article from the National Institute of Health titled “Radiation as a Risk Factor for Cardiovascular Disease” stating that radiation can place individuals at an increased risk of developing cardiovascular disease. In the medical opinion dated February 18, 2013, [M. A], M.D., F.A.C.C., F.A.C.P., opined that it is as likely as not that the nuclear radiation the Veteran was exposed to contributed to his aortic valve stenosis. 4. We disagree with the opinion included in the file. There is no discussion of the Veterans’ actual radiation dose. None of the submitted articles make a nexus for causation of disease based on the Veterans’ actual radiation dose. Radiation dose is the prime factor to consider when determining causation of disease. Where presumption does not exist1, exposure to radiation, alone, is not the cause of disease. The dose must be determined through direct measurement or reconstruction methodology. Once the dose is determined, the issue of disease causation can be addressed. We have the dose estimate as provided by DTRA (not more than 18.5 rem to the heart and its supporting blood vessels). The skin dose of 550 rem is not applicable to heart disease, as it is only reported for use in the instance of skin disease. 5. Several studies have shown that late changes of fibrosis can be seen in the heart muscle, arteries and valves. The patients involved usually received doses to the mediastinum ranging from 30 to 70 gray (3000 to 7000 rad)2. The Veterans dose, of 18.5 rem (or rad) to the heart, is less than 1% of this threshold. Wong and colleagues3 evaluated the relation between exposure to radiation and the incidence of 19 non-malignant disorders using data from atomic bomb survivor studies. They could not detect statistically significant relationships for several diseases including hypertension, hypertensive heart disease, or ischemic heart disease. In summary, there is no evidence linking non-cancer diseases with radiation doses of less than 50 rem in the population group (atomic bomb survivors) most likely to demonstrate a dose-response. 6. In view of the above, it is our opinion that, it is not likely that the Veterans’ cardiovascular disability (to include aortic stenosis, coronary artery disease, and/or hypertension) was caused by exposure to ionizing radiation during military service. Footnote references: 1. 38 C.F.R. § 3.309(d). 2. Mettler and Upton. Medical Effects of Ionizing Radiation. Elsevier, 2008. Pp. 316-320. 3. Wong FL, Yamada H, Sasaki K et al. Non-cancer disease incidence in the atomic bomb survivors: 1958-1986. Radiation Research. 135:135-142, 1993. In October 2020, the Executive Director Compensation Service provided the AOJ with a memorandum on the Advisory Opinion - Radiation Review Under 38 C.F.R. § 3.311. The radiation review opinion was included. The memorandum provided as follows: We have reviewed your memorandum request for an advisory opinion, dated September 16, 2020, as well as the Board of Veterans’ Appeals remand of September 21, 2017, along with the Veteran’s record. The Veteran’s claim is for entitlement to service connection for a cardiovascular disability, to include aortic stenosis, coronary artery disease (CAD) and/or hypertension, due to exposure to ionizing radiation during service. He contends exposure to radiation while performing his duties aboard the USS Perkins (DDR877) during Operation Hardtack I at Enewetak and Bikini Atolls in the Pacific, as well as during liberty on Bikini for recreation. We referred this case to the Under Secretary for Health for an advisory medical opinion. The October 18, 2020 advisory medical opinion from the Director, Post-9/11 Era Environmental Health Service (12POP5), written for the Under Secretary for Health (USH) concluded that it is not likely that the Veteran’s cardiovascular disability (to include aortic stenosis, coronary artery disease, and/or hypertension) was caused by exposure to ionizing radiation during military service. It was noted that the Defense Threat Reduction Agency (DTRA) confirmed the Veteran as a participant of Operation Hardtack I, a U.S. atmospheric nuclear test series conducted at the Pacific Proving Ground in 1958 and provided the doses the Veteran could have received during his participation. The dose estimate to the heart and its supporting blood vessels was determined to be not more than 18.5 rem. The Veteran’s service records contain DD Form 1141, Record of Exposure to Ionizing Radiation, for the period of April 6, 1958 to May 22, 1958. The recorded dose was not added to the estimate provided by DTRA, as the estimated dose accounts for all measured doses and adds a considerable factor. The USH opinion references several studies showing that late changes of fibrosis can be seen in the heart muscle, arteries and valves, but the patients involved usually received doses to the mediastinum ranging from 30 to 70 gray (3000 to 7000 rad). The Veteran’s dose of 18.5 rem (rad) to the heart is less than 1% of this threshold. A study by Wong and colleagues was unable to detect statistically significant relationships for several diseases including hypertension, hypertensive heart disease, or ischemic heart disease. It was summarized that there is no evidence linking non-cancer diseases with radiation doses of less than 50 rem in the population group (atomic bomb survivors) most likely to demonstrate a dose response. The Veteran’s cardiovascular disability was reported approximately twenty-four years after exposure to ionizing radiation. He was 26 years old at the time of exposure to ionizing radiation. The Veteran is a Caucasian male and a nonsmoker. He reported no family history of cancer. Medical records show the Veteran’s mother had a history of heart disease, hyperlipidemia, and hypertension. The Veteran is a retired engineer. No post-service radiation exposure is noted or reported. It is noted that sometimes an opinion will be received which basically states, “X is due to radiation”. However, the opinion will often not consider the actual level of radiation exposure. Such opinions would clearly be flawed. To have probative value, a medical opinion must contain not only clear conclusions with supporting data, but also a reasoned medical explanation connecting the two. Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008). It is well established that medical opinions that are speculative, general, or inconclusive in nature do not provide a sufficient basis upon which to support a claim. McLendon v. Nicholson, 20 Vet. App. 79, 85 (2006). Further, as noted such an opinion would not be consistent with sound scientific evidence. The Court has held that to allow the opinions of individual doctors to trump the collective view of experts would be an impermissible expansion of available remedies beyond those explicitly provided by Congress. Nevertheless, “it is the total analysis provided by the medical professional that must be weighed and considered by the Board. Id; see also Allday, supra.” Polovick v. Shinseki, April 22, 2009, No. 06-3024. As noted, the opinion does not consider actual exposure level and is therefore not probative. Based on the scientific evidence referenced in the memorandum from the VA Under Secretary for Health and our review of the evidence in its entirety, it is our opinion that there is no reasonable possibility that the Veteran’s cardiovascular disability (to include aortic stenosis, coronary artery disease, and/or hypertension) is the result of ionizing radiation exposure during military service. The Board finds that the assessment by the DTRA and October 2020 VA Radiation Review opinion are more probative than M.A.’s 2013 opinion. The DTRA has more expertise in the area of dose assessment, as well as a more accurate, detailed record of the Veteran's in-service opportunities for exposure. It considered the entirety of the Veteran's history, but still found that the dosage was not sufficient to have caused any of the Veteran's cardiovascular conditions. We note that Dr. A.’s report has no substantive rationale and does not reflect an assessment of dose. His treatment records provide no additional basis to support his assertion as to causation. These facts make it less probative, as referenced in the Director’s memorandum. We note again that the dose estimate in this case has been challenged with argument but find that the preponderance of the evidence is against finding that the DTRA estimate did not constitute sound scientific evidence. The Veteran notes the article indicating dose estimates may be inaccurate and the representative essentially argues that the information is outdated and inaccurate. See January 2021 argument from Veteran and representative. The Director’s opinion as well as the discussion in the Radiation Review Memorandum cite to the fact that the dose estimate is considered to reflect a much higher dose than his actual measured dose and indeed on that benefits the Veteran. The preponderance of the evidence is against finding against the opinion or the dose estimate. Articles submitted by the Veteran are not specific to this claim and do not advance the theory that the current cardiovascular disease is due to the atmospheric radiation exposure received by this Veteran in his naval service and are outweighed by the findings of the DTRA as well as the October 2020 VA medical opinion. As the requirements of 38 C.F.R. § 3.311 have not been met, service connection cannot be granted under that regulation. Having considered the possibility of both presumptive service connection and the application of the provisions of 38 C.F.R. § 3.311, the Board must also consider service connection without reference to the radiation regulations. The regulations governing service connection for radiation exposure do not preclude a Veteran from establishing service connection with proof of actual direct causation. Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). Direct service connection generally requires (1) medical evidence of a current disability; (2) medical or, in certain circumstances, lay evidence of in-service incurrence or aggravation of a disease or injury; and (3) medical evidence of a nexus between the claimed in-service disease or injury and the present disability. Hickson v. West, 12 Vet. App. 247, 253 (1999). As discussed above, the Board finds the aforementioned VA opinion, based on the DTRA dose assessments, as well as the Veteran's exposure history, to be more probative than Dr. A.'s opinion. Additionally, the Board notes that the authors of the October 2020 VA opinion found that the claimed cardiovascular disorder was not likely caused by exposure to ionizing radiation during military service. In   formulating this opinion, they reviewed the claims file and considered the Veteran's lay statements regarding his in-service exposure to ionizing radiation and symptomatology he experienced therein and the articles he advanced in support of his claim. They disagreed with Dr. A.’s opinion, citing that he did not discuss the actual radiation dose. They noted that none of the articles submitted suggest a causal nexus between the causation of the heart disease and the actual radiation dose. There is no other competent evidence of actual, direct causation. The Board acknowledges the Veteran's sincere belief that his cardiovascular disorder is related to his in-service radiation exposure. While he is competent and credible to report to report in-service experiences and symptoms of his post-service chronic cardiovascular ailments, the question of whether the in-service and/or post-service symptomatology is related to radiation exposure is not capable of lay observation. It requires clinical testing to assess and diagnose the underlying condition and training to make the appropriate interpretations and conclusions about what the testing demonstrates in conjunction with the symptoms reported to determine the cause. In other words, mere observable symptomatology is insufficient. As such, the Board finds that the Veteran's statements as to how his claimed cardiovascular condition developed is not competent evidence as to a nexus. We further note that cardiovascular disease was not noted, manifest or diagnosed during service or within one year of separation. The fact that the heart, vascular system and blood pressure were normal in October 1959 and December 1960 establish that he did not have characteristic manifestations of the disease process. Rather, there was a remote onset unrelated to service.   For the foregoing reasons, the claim for service connection for a cardiovascular disability, to include aortic stenosis, CAD and/or hypertension, is denied. In arriving at the decision to deny this claim, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, as the preponderance of the evidence is against the claim, that doctrine is not applicable. See 38 U.S.C. § 5107 (b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49, 53-56 (1990). H. N. SCHWARTZ Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board N. RIPPEL The Board’s decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.