Citation Nr: 22019751 Decision Date: 04/02/22 Archive Date: 04/02/22 DOCKET NO. 15-12 243A DATE: April 2, 2022 ORDER Entitlement to a rating in excess of 10 percent for coronary artery disease (CAD) prior to June 3, 2015 is denied. Entitlement to a rating in excess of 30 percent for CAD from June 3, 2015 is denied. REMANDED Entitlement to service connection for a bilateral foot disability is remanded. Entitlement to service connection for peripheral neuropathy of the bilateral lower extremities is remanded. Entitlement to a total disability rating based on individual unemployability due to service-connected disabilities (TDIU) prior to June 3, 2015 is remanded. FINDINGS OF FACT 1. Prior to June 3, 2015, the Veteran's CAD required treatment with continuous medication; metabolic equivalent (MET) testing shows that a workload greater than 7.0 METs but not greater than 10.0 METs results in dyspnea and angina, but no such probative symptoms at a workload of 7.0 METs or less; and there is no evidence of cardiac hypertrophy or dilatation on electrocardiogram, echocardiogram, or X-ray. 2. From June 3, 2015, the Veteran's CAD shows evidence of cardiac hypertrophy or dilatation; metabolic equivalent (MET) testing shows that a workload greater than 5.0 METs but not greater than 7.0 METs results in dyspnea, fatigue, angina, and dizziness, but no such probative symptoms at a workload of 5.0 METs or less; and there is no evidence of left ventricular dysfunction with an ejection fraction of 30 to 50 percent or more than one episode of active congestive heart failure in the past year. METs testing also did not show METs testing resulting in heart failure symptoms at a workload of 5.0 METs or less. CONCLUSIONS OF LAW 1. Prior to June 3, 2015, the criteria for rating in excess of 10 percent for CAD have not been met. 38 U.S.C. §§ 1155, 5107 (2012); 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.100, 4.104, Diagnostic Code 7005 (2021). 2. From June 3, 2015, the criteria for a rating in excess of 30 percent for CAD have not been met. 38 U.S.C. §§ 1155, 5107 (2012); 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.100, 4.104, Diagnostic Code 7005 (prior to and from Nov. 14, 2021). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from January 1966 to August 1968. This matter is before the Board of Veterans' Appeals (Board) on appeal from a May 2013 rating decision of a Department of Veterans Affairs (VA) Regional Office (RO). In November 2018, a hearing was held before the undersigned. A transcript of the hearing is of record. The case was previously before the Board in July 2019 when it was remanded for further development. While on remand, in a March 2021 decision, the RO granted entitlement to TDIU effective June 3, 2015. However, as the Veteran was not awarded TDIU for the entire period on appeal, the issue of entitlement to TDIU prior to June 3, 2015 is still before the Board. Increased Rating-CAD The Veteran seeks an increased rating in excess of 10 percent for his service-connected CAD prior to June 3, 2015 and in excess of 30 percent from June 3, 2015. Effective November 14, 2021, VA amended the rating criteria for arteriosclerotic heart disease (coronary artery disease) under 38 C.F.R. § 4.104, Diagnostic Code (DC) 7005. 86 Fed. Reg. 54089 (Sep. 30, 2021). This amended regulation applies to all applications for benefits received by VA or that are pending before the agency of original jurisdiction on or after November 14, 2021. Claims pending prior to the effective date will be considered under both the pre- and post-amendment rating criteria, and whichever is more favorable to the Veteran will be applied. However, the Board may not apply the post-amendment rating criteria to a period prior to its effective date, unless the regulation explicitly provides otherwise. Kuzma v. Principi, 341 F.3d 1327 (Fed. Cir. 2003). Conversely, the Board is not precluded from applying the pre-amendment rating criteria to a period on or after the effective date of the post-amendment rating criteria so long as it was in effect during the pendency of the appeal. Prior to November 14, 2021, under 38 C.F.R. § 4.104, DC 7005, for arteriosclerotic heart disease (coronary artery disease) a 10 percent rating is warranted where a workload of greater than 7.0 metabolic equivalents (METs) but not greater than 10.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; continuous medication is required. A 30 percent rating is warranted where a workload of greater than 5.0 METs but not greater than 7.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; there is cardiac hypertrophy or dilatation on electrocardiogram, echocardiogram, or X-ray. A 60 percent rating is warranted where there is more than one episode of acute congestive heart failure in the past year, or; a workload of greater than 3.0 METs but not greater than 5.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; left ventricular dysfunction with an ejection fraction of 30 to 50 percent. A 100 percent rating is warranted where there is chronic congestive heart failure, or; a workload of 3.0 METs or less results in dyspnea, fatigue, angina, dizziness, or syncope, or; left ventricular dysfunction with an ejection fraction of less than 30 percent. Under the pre-amendment rating criteria, one MET is defined as the energy cost of standing quietly at rest and represents an oxygen uptake of 3.5 milliliters per kilogram of body weight per minute. 38 C.F.R. § 4.104, Note (2). When the level of METs at which dyspnea, fatigue, angina, dizziness, or syncope develops is required for evaluation, and a laboratory determination of METs by exercise testing cannot be done for medical reasons, an estimation by a medical examiner of the level of activity (expressed in METs and supported by specific examples, such as slow stair climbing or shoveling snow) that results in dyspnea, fatigue, angina, dizziness, or syncope may be used. Id. Whether or not cardiac hypertrophy or dilatation (documented by electrocardiogram, echocardiogram, or X-ray) is present and whether or not there is a need for continuous medication must be ascertained in all cases. Even if the requirement for a 10 percent (based on the need for continuous medication) or 30 percent (based on the presence of cardiac hypertrophy or dilatation) evaluation is met, METs testing is required in all cases except: (1) When there is a medical contraindication. (2) When the left ventricular ejection fraction has been measured and is 50% or less. (3) When chronic congestive heart failure is present or there has been more than one episode of congestive heart failure within the past year. (4) When a 100 percent evaluation can be assigned on another basis. If left ventricular ejection fraction (LVEF) testing is not of record, evaluate based on the alternative criteria unless the examiner states that the LVEF test is needed in a particular case because the available medical information does not sufficiently reflect the severity of the veteran's cardiovascular disability. 38 C.F.R. § 4.100. For the purposes of a 60 percent evaluation, the pre-amendment rating criteria do not require a separate showing of left ventricular dysfunction in addition to an ejection fraction of 30 to 50 percent. Otero-Castro v. Principi, 16 Vet. App. 375, 382 (2002). Additionally, the phrase "30 to 50 percent" means 30 percent through 50 percent. Id. at 380. For the purposes of a 100 percent evaluation, the pre-amendment rating criteria do not require a separate showing of left ventricular dysfunction in addition to an ejection fraction of less than 30 percent. See id. at 382. Effective November 14, 2021, under 38 C.F.R. § 4.104, DC 7005, arteriosclerotic heart disease (coronary artery disease) is rated in accordance with the General Rating Formula for Diseases of the Heart. A 10 percent rating is warranted where a workload of 7.1-10.0 METs results in heart failure symptoms, or continuous medication is required for control. A 30 percent rating is warranted where a workload of 5.1-7.0 METs results in heart failure symptoms, or where there is cardiac hypertrophy or dilatation confirmed by echocardiogram or equivalent (e.g., multigated acquisition scan or magnetic resonance imaging). A 60 percent rating is warranted where a workload of 3.1-5.0 METs results in heart failure symptoms. A 100 percent rating is warranted where a workload of 3.0 METs or less results in heart failure symptoms. Under the post-amendment rating criteria, one MET is defined as the energy cost of standing quietly at rest and represents an oxygen uptake of 3.5 milliliters per kilogram of body weight per minute. 38 C.F.R. § 4.104, Note (2). When the level of METs at which breathlessness, fatigue, angina, dizziness, or syncope develops is required for evaluation, and a laboratory determination of METs by exercise testing cannot be done for medical reasons, an estimation by a medical examiner of the level of activity (expressed in METs and supported by specific examples, such as slow stair climbing or shoveling snow) that results in those symptoms may be used. Id. For purposes of the General Rating Formula for Diseases of the Heart, heart failure symptoms include, but are not limited to, breathlessness, fatigue, angina, dizziness, arrhythmia, palpitations, or syncope. 38 C.F.R. § 4.104, Note (3). The post-amendment rating criteria also provide that the presence or lack thereof of cardiac hypertrophy or dilatation (documented by electrocardiogram, echocardiogram, or X-ray) and the need or lack of need for continuous medication must be ascertained in all cases. 38 C.F.R. § 4.100. Additionally, even if the requirement for a 10 percent (based on the need for continuous medication) rating or a 30 percent (based on the presence of cardiac hypertrophy or dilatation) evaluation is met, METs testing is required in all cases except: (1) When there is a medical contraindication, or (2) when a 100 percent evaluation can be assigned on another basis. The Veteran underwent a VA examination in December 2010. The Veteran's treatment plan included taking continuous medication. The Veteran did not have congestive heart failure. An interview based METs test revealed a level of >7 to 10 METs with symptoms of dyspnea and angina. The METs level was noted to be consistent with activities such as climbing stairs quickly, moderate bicycling, sawing wood, or jogging (6 miles per hour). There was no evidence of cardiac hypertrophy or dilatation. An April 2010 echocardiogram showed LVEF of 65 percent. The examiner noted that heavy exertion caused shortness of breath and chest pain. A July 2011 cardiac ultrasound report noted that the mitral valve showed thickened mitral annulus and minimally enlarged aortic root. Calculated ejection fraction was 65 percent, no hypertrophy, and no abnormal wall motion. There was no pericardial abnormality. Right atrium and right ventricular dimensions were normal, and there was no significant interval tracing change. In a February 2012 statement, the Veteran stated that he had increased shortness of breath and would be winded and dizzy when walking short distances. He also had recent chest pains which last one hour and leave him weak and tired. The Veteran underwent a VA examination in April 2013. The Veteran took continuous medication for control of his heart condition, but there had not been a change in his medications. He did not have congestive heart failure. The examiner stated that the Veteran was diagnosed with ischemic heart disease in 2008, but there were no objective symptoms or physical findings on testing, therefore there were no findings consistent with a diagnosis of ischemic heart disease. The most recent diagnostic exercise testing in 2011 showed a METs level of 5.4. There was no evidence of cardiac hypertrophy or dilatation. A May 2013 echocardiogram showed LVEF of 55 percent. The Veteran had occasional chest pain about 1 to 2 times a week that last a second or so. He was able to perform all his activities of daily living, clean the house, cook meals, and go shopping without difficulty. The examiner stated that any limitations were due to non-related conditions and not the Veteran's heart problems. In a May 2013 addendum opinion, the examiner clarified that there was a clear diagnosis of ischemic heart disease. The examiner indicated that METs level based on the ischemic heart disease alone would still be estimated at > 7 to 10 as the ejection fraction was still unchanged since 2010 at 55 percent (normal) with no new or increased symptoms due to ischemic heart disease since the last ratings exam. She indicated that the Veteran had worsening dyspnea most likely due to worsening lung condition and the need for chronic oxygen. The Veteran underwent a VA examination in February 2015. Continuous medication was required for control of the Veteran's heart condition. The Veteran did not have a myocardial infarction, congestive heart failure, arrhythmia, heart valve condition, infectious heart condition, or pericardial adhesions. There was no evidence of cardiac hypertrophy or cardiac dilatation. A February 2015 echocardiogram showed LVEF of 60 percent, with normal wall motion and normal wall thickness. An interview based METs test revealed a level of >3 to 5 METs with symptoms of dyspnea and angina. This METs level was noted to be consistent with activities such as light yard work (weeding), mowing the lawn (power mower), and brisk walking (4 miles per hour). The examiner estimated that 30 percent of the METs level limitation was due solely to the heart condition. COPD had a 40 percent effect on the Veteran's METs level and lower extremity neuropathy had a 30 percent effect on the Veteran's METs level. The Veteran's heart condition impacted his ability to work in that he got short of breath with mild activity, such as blowing and picking up leaves, walking, and riding stationary bike. The examiner stated that the ejection fraction was the most accurate indicator of the Veteran's current cardiac functioning, as it was based on an actual test, while the interview METs test was based on an estimation of what the Veteran stated he was physically able to do. The February 2015 echocardiogram found a normal chamber size, normal function with ejection fraction of 60 percent, unremarkable valves, mild aortic valve sclerosis, and no masses, thrombus, or effusion. A June 3, 2015 echocardiogram noted that it was a technically difficult study and a poor quality echocardiogram. The interpreting physician indicated that the left and right atrial size and AV groove size were probably normal. Left and right ventricle size probably had normal size and function. Ejection fraction was 60 percent. The valves were noted to be unremarkable with no significant valvular regurgitation or stenosis, and no masses, thrombus, or effusion. The Veteran underwent a VA examination in May 2018. Continuous medication was required for control of the Veteran's heart condition. The Veteran did not have a myocardial infarction, congestive heart failure, arrhythmia, heart valve condition, infectious heart condition, or pericardial adhesions. There was no evidence of cardiac hypertrophy or cardiac dilatation. A June 2015 echocardiogram showed LVEF of 63 percent, with abnormal result (which is described above). An interview based METs test revealed a level of >3 to 5 METs with symptoms of dyspnea, fatigue, angina, and dizziness. The examiner estimated that the METs level limitation was due solely to the heart condition. The Veteran's heart condition impacted his ability to work in that he had exertional dyspnea nad chest pain that impacted his physical and sedentary employment. The examiner indicated that the ejection fraction was the most accurate indicator of the Veteran's current cardiac functioning since it shows the real functional capacity for the heart. The examiner noted that the interview based METs estimation was subjective and affected by other body systems including the lungs, heart, and musculoskeletal systems. VA treatment records from May 2018 note complaints of chest pain. The Veteran admitted to chest pain and dyspnea on exertion. He was assessed with angina. In April 2019, it was noted that his coronary artery disease was stable and there was no recent chest pain. In September 2019, he denied frequent chest pain. An October 2018 echocardiogram noted a normal LV systolic function, with estimated LVEF of 60 to 65 percent. There was normal ventricular size and function. There was mild biatrial dilation, mild tricuspid regurgitation, trivial mitral regurgitation, and mild elevation of pulmonary artery pressure was suggested. In May 2020, the May 2018 VA examiner provided an addendum opinion, in which he stated that the ejection fraction from the Veteran's LVEF was more accurate than his estimated METs from subjective complaints. VA treatment records from March 2021 note the Veteran having complained of shortness of breath, sharp chest pain, and dyspnea on exertion. The Veteran underwent a stress test which showed no evidence of pharmacologically inducible ischemia, no inducible dysrhythmias, and normal hemodynamic response to testing. For the period prior to June 3, 2015, considering all relevant evidence of record, the Board concludes that the Veteran's CAD does not warrant a rating in excess of 10 percent under DC 7005. Symptoms shown during this time period include METs level of > 7 to 10 with symptoms of dyspnea and angina. Although the February 2015 VA examiner indicated > 3 to 5 METs with symptoms of dyspnea and angina, it was estimated that only 30 percent of the METs level limitation was due solely to the heart condition and that the METs level limitations were attributable at a greater percentage (70 percent combined) to COPD and lower extremity neuropathy. The examiner also found no evidence of cardiac hypertrophy or cardiac dilatation. A higher 30 percent rating under DC 7005 is not warranted unless a workload of greater than 5.0 METs but not greater than 7.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; there is cardiac hypertrophy or dilatation on electrocardiogram, echocardiogram, or X-ray. As discussed above, an April 2013 VA examiner noted that the most recent diagnostic exercise testing in 2011 showed a METs level of 5.4. However, in a May 2013 addendum opinion, the examiner indicated that METs level based on ischemic heart disease alone would still be estimated at > 7 to 10 since the ejection fraction was still unchanged since 2010 at 55 percent with no new or increased symptoms due to ischemic heart disease. The examiner also noted that any limitations were due to non-related conditions, including the Veteran's worsening lung condition and not the Veteran's heart problems. The examiner indicated that there was no evidence of cardiac hypertrophy or dilatation. As such, the notation of a METs level of 5.4 in 2011 cannot serve as the basis for a 30 percent rating as the examiner found that all limitations were attributable to non-related conditions. Thus, the Board concludes that the Veteran's CAD did not meet the criteria corresponding to a higher 30 percent rating under DC 7005 prior to June 3, 2015. For the period from June 3, 2015 considering all relevant evidence of record, the Board finds that the Veteran's CAD does not warrant a rating in excess of 30 percent under DC 7005. A higher 60 percent rating under DC 7005 is not warranted unless there is more than one episode of acute congestive heart failure in the past year, or; a workload of greater than 3.0 METs but not greater than 5.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; there is left ventricular dysfunction with an ejection fraction of 30 to 50 percent. As discussed above, the evidence does not show that the Veteran had congestive heart failure, and LVEF readings were no less than 60 percent. While the May 2018 VA examiner indicated that an interview based METs test revealed a level of >3 to 5 METs with symptoms of dyspnea, fatigue, angina, and dizziness, the examiner emphasized that the ejection fraction of 63 percent from the Veteran's LVEF was more accurate than his estimated METs from subjective complaints. Thus, the Board concludes that the Veteran's CAD did not meet the criteria corresponding to a higher 60 percent rating under DC 7005. Also considering the amended criteria, the Board finds that the Veteran's CAD does not warrant a rating in excess of 30 percent under DC 7005. The evidence discussed above is persuasively against a finding of a workload of 3.1-5.0 METs that results in heart failure symptoms, which would warrant a higher 60 percent rating under the amended criteria. The Board notes that the Veteran is competent to report his readily observable symptoms. Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007). The Veteran has indicated that he has experienced symptoms such as chest pains, shortness of breath, and dizziness. The Board acknowledges the Veteran's belief that his heart symptoms are more severe than as reflected by the currently assigned ratings. However, the Veteran is not competent to provide an opinion regarding the severity of his symptomatology in accordance with the rating criteria and whether his symptoms are from his heart disability or another non-heart related condition. See Woehlaert v. Nicholson, 21 Vet. App. 456 (2007) (although the claimant is competent in certain situations to provide a diagnosis of a simple condition such as a broken leg or varicose veins, the claimant is not competent to provide evidence as to more complex medical questions). Rather, the Board finds the medical evidence in which professionals with medical expertise examined the Veteran, acknowledged his reported symptoms, and described the manifestations of such disability in light of the rating criteria to be more persuasive than his reports regarding the severity of such condition. In sum, the Board finds that prior to June 3, 2015, a rating in excess of 10 percent for CAD is not warranted. Also, from June 3, 2015, the Board finds that a rating in excess of 30 percent for CAD is not warranted. In reaching such determination, the Board has considered the applicability of the benefit of the doubt doctrine. However, as the evidence persuasively weighs against the Veteran's claim, that doctrine is not applicable, and the claim must be denied. 38 U.S.C. § 5107; 38 C.F.R. §§ 4.3, 4.7; Lynch v. McDonough, No. 2020-2067, 2021 U.S. App. LEXIS 37307 (Fed. Cir. Dec. 17, 2021). REASONS FOR REMAND Entitlement to service connection for a bilateral foot disability The RO obtained a VA examination and opinion regarding the Veteran's bilateral foot disability in March 2021. The examiner indicated that the condition clearly and unmistakably existed prior to service and was clearly and unmistakably not aggravated beyond natural progression in service. The rationale provided was that there was no evidence to indicate that the Veteran continued to suffer from the disorder during service, which was typical of the condition. However, the progression was not beyond normal progression for this disorder and no evidence of permanent aggravation beyond normal progression was identified. The examiner indicated that there was no evidence that the Veteran continued to suffer from a foot disability in service, but then also referred to a "progression" of the Veteran's condition in service. It is not clear from what the examiner provided as to what was meant by that statement. In addition, no other rationale was provided. Another remand is unfortunately necessary. See Barr v. Nicholson, 21 Vet. App. 303, 312 (2007) (finding that when VA undertakes to provide a VA examination or obtain a VA opinion, even if not statutorily obligated to do so, it must ensure that the examination or opinion is adequate). Entitlement to service connection for peripheral neuropathy of the bilateral lower extremities The Board's July 2019 remand directed that the Veteran be afforded a VA examination to determine whether it was at least as likely as not that the Veteran's peripheral neuropathy of the bilateral lower extremities was related to his service, to include exposure to herbicide agents. A VA examination was obtained in October 2019. The examiner provided a diagnosis of unspecified myopathy with peripheral neuropathy in the bilateral lower extremities. The examiner indicated that September 2010 VA treatment records indicated that extensive testing was done and it was reported that the Veteran had a myopathy that was a progressive congenital myopathy, making it less likely than not to be caused by active duty service. Although the examiner commented on the Veteran's myopathy, there was no discussion of the comment from September 2010 that there was a possible proximal myopathy with an unrelated sensory neuropathy. The claims file also contains various diagnoses of neuropathy, including peripheral neuropathy and distal neuropathy. Also, in July 2013 VA neurology treatment records indicate that Agent Orange may be the cause of sensory polyneuropathy. As the examiner did not provide a complete rationale and did not consider other relevant evidence of record, remand is needed for an addendum opinion. Entitlement to TDIU prior to June 3, 2015 Finally, because a decision on the remanded issues could significantly impact a decision on the issue of entitlement to TDIU, the issues are inextricably intertwined. A remand of the claim for TDIU is required. See Harris v. Derwinski, 1 Vet. App. 180, 183 (1991). Also, updated VA treatment records should be obtained on remand. The matters are REMANDED for the following actions: 1. Obtain the Veteran's VA treatment records for the period from July 2021 to the present. 2. After completing the above development, return the claims file to the VA examiner who conducted the March 2021 VA foot disorder examination for an addendum medical opinion. The electronic claims file must be made available to the reviewing clinician, and the clinician must specify in the opinion that the file has been reviewed. If the VA examiner who provided the March 2021 opinion is not available, then forward the Veteran's claims file to another appropriate specialist to obtain the below requested medical opinion. Another examination of the Veteran must be performed only if deemed necessary by the reviewing clinician. After a review of the claims file, the examiner must provide opinions as to the following: a) Did the Veteran's bilateral pes planus, which existed prior to service, at least as likely as not (approximately a 50 percent or greater probability) increase in severity during service? b) If so, was the increase in severity clearly and unmistakably (undebatable) due to the natural progress of the disease? A complete rationale for all opinions must be provided. If the clinician cannot provide a requested opinion without resorting to speculation, it must be so stated, and the clinician must provide the reasons why an opinion would require speculation. The clinician must indicate whether there was any further need for information or testing necessary to make a determination. Additionally, the clinician must indicate whether any opinion could not be rendered due to limitations of knowledge in the medical community at large and not those of the particular examiner. 3. Also obtain an addendum medical opinion from an appropriate VA examiner (preferably a neurologist) regarding the Veteran's claim for service connection for peripheral neuropathy of the bilateral lower extremities. The electronic claims file must be made available to the reviewing clinician, and the clinician must specify in the opinion that the file has been reviewed. Please also review the complete copy of this remand. Another examination of the Veteran must be performed only if deemed necessary by the reviewing clinician. The examiner must provide an opinion as to whether it is at least as likely as not (approximately a 50 percent probability or greater) that the Veteran's peripheral neuropathy or idiopathic progressive neuropathy of the bilateral lower extremities is related to the Veteran's service, to include exposure to herbicide agents during active duty. The examiner must note that applicable VA law establishes that the legal provision for presumptive service connection does not otherwise preclude a veteran from establishing service connection with proof of actual direct causation, even if a disorder is not one for which service connection is presumed. (Continued on the next page) A complete rationale for all opinions must be provided. The clinician must review the various diagnoses in the record and provide a reasoned medical explanation for the opinion, and address all deficiencies discussed in this remand. If the clinician cannot provide a requested opinion without resorting to speculation, it must be so stated, and the clinician must provide the reasons why an opinion would require speculation. The clinician must indicate whether there was any further need for information or testing necessary to make a determination. Additionally, the clinician must indicate whether any opinion could not be rendered due to limitations of knowledge in the medical community at large and not those of the particular examiner. M. SORISIO Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Bonnie Yoon, Counsel 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.