A 70-year-old man presented with 3 months of progressive exertional dyspnea and worsening orthopnea consistent with New York Heart Association Class III symptoms. Past medical history was significant for coronary artery disease (for which he underwent remote coronary artery bypass grafting and percutaneous coronary intervention), hypertension, atrial fibrillation, non-insulin-dependent diabetes mellitus, chronic obstructive pulmonary disease, and peripheral arterial disease. His exam revealed normal vital signs, a grade III/VI crescendo-decrescendo murmur over the right-upper sternal border with diminished S2 and radiation to the left carotid artery, and a III/VI holosystolic murmur over the apex with radiation to the axilla; an S3 was present. A transthoracic echocardiogram showed low-normal left ventricular ejection fraction (LVEF) of 50-55%, basal, inferolateral, and inferior wall hypokinesis with eccentric, posteriorly directed moderate-to-severe (3+) ischemic mitral regurgitation (MR). In addition, he had a calcified aortic valve with restricted opening. By continuity equation, his calculated aortic valve area was 0.8 cm2, with mean aortic gradient of 26 mm Hg, aortic valve peak velocity of 3.1 m/sec, and dimensionless index of 0.18. His left ventricular stroke volume index was reduced at 30 ml/m2. Overall, these findings were consistent with paradoxical low-flow, low-gradient severe aortic stenosis (AS) with preserved LVEF (Videos 1-2). A transesophageal echocardiogram confirmed these findings. A gated chest computed tomography angiography showed a heavily calcified aorta and a measured aortic valve calcium score of 2099 Agatston units. In addition, a left lower-lobe lung mass was found that turned out to be localized adenocarcinoma (T1bN0M0), which has a good prognosis if surgically resected. Because his calculated Society of Thoracic Surgeons Predicted Risk of Mortality score was 8.4% for isolated aortic valve replacement and because of his porcelain aorta, concomitant significant MR, and peripheral arterial disease, the patient was deemed to be of high surgical risk and referred for heart team discussion.
Video 1
Video 2
Given the mixed valvular disease, what would you recommend?
Show Answer
The correct answer is: C. Staged TAVR followed by MR severity reassessment
The patient had primary lung adenocarcinoma that was localized and operable, thus he had a good prognosis from that standpoint if only he would be optimized for a noncardiac surgery. The heart team discussion involved cardiologists and cardiothoracic surgeons. Given his multiple comorbidities, significant heart failure symptoms, and prior reports indicating MR improvement post TAVR,1-3 the plan was to proceed with TAVR first and follow with re-evaluation of his MR severity and left lower-lobe lobectomy versus nonoperative ablative options. Following TAVR, he continued to have dyspnea on exertion (although to a lesser degree). A repeat transthoracic echocardiogram demonstrated persistent moderate-to-severe MR (3+), effective regurgitant orifice area of 0.35 cm2, and regurgitant volume of 53 ml/beat (Video 3). After extensive discussion with the patient, family, and medical colleagues, 8 weeks after TAVR, the patient underwent left posterolateral thoracotomy, mitral valve replacement on a beating heart with no aortic cross-clamp (#33 mm Medtronic bioprosthesis), and left lower-lobe lobectomy with lymph node dissection. Post-procedure, he recovered gradually and had significant relief of his exertional dyspnea at his 8-week follow-up visit.
Video 3
To date, there are no randomized controlled trials evaluating treatment strategies for high-risk patients with mixed significant AS and MR. With a surgical approach, both valves get operated on simultaneously. With a percutaneous approach, however a staged procedure with reassessment is usually required. Based on published data thus far, the step-wise approach for high-risk patients is usually to replace the aortic valve first and then reassess the severity of the MR. In cohort A of the PARTNER (Placement of Aortic Transcatheter Valves) trial,1 approximately 19.6% of patients undergoing TAVR had moderate-to-severe MR, of which 58% had improvement in the degree of MR post-TAVR. In a recent meta-analysis2 including 521 patients with severe AS and moderate-to-severe MR who underwent TAVR, 50.5% of these patients had regression of their MR severity during a mean follow-up of 180 days. As expected, patients with functional MR tend to have more significant MR regression in comparison with patients with organic/primary MR.3-5 This case was both unusual and complex in the medical decision-making process given multiple valvular pathologies and primary lung malignancy. Usually when high-risk surgical patients present with severe AS and MR, they are referred for TAVR followed by reassessment of symptoms and MR severity. If MR remains moderately severe after TAVR, then a percutaneous mitral valve repair procedure can be considered if anatomically suitable. In our case, it was decided to proceed with a surgical MVR given the concomitant need for surgical lung lobectomy. In conclusion, high-surgical-risk patients with mixed AS and MR present a clinical dilemma. The percutaneous staged approach of TAVR followed by percutaneous mitral valve repair is technically feasible and pathologically plausible, further large-scale studies are needed. Importantly, individualization of treatment strategies will remain the cornerstone, and this is best done within the heart team.
Answer A is not the best answer because severe MR might not regress with TAVR alone. Answers B and D are incorrect because there is not a plausible mechanism by which severe AS will improve with repair or replacement of the mitral valve. Additionally, based on the discussion above, MR (specifically functional MR) might regress with TAVR alone. Answer E is incorrect because the patient had decompensated heart failure secondary to valvular heart disease, including severe AS where medical therapy alone doesn't affect the outcome; the localized primary lung malignancy had a good prognosis if treated surgically (i.e., valve treatment was not futile care).
References
Barbanti M, Webb JG, Hahn RT, et al. Impact of preoperative moderate/severe mitral regurgitation on 2-year outcome after transcatheter and surgical aortic valve replacement: insight from the Placement of Aortic Transcatheter Valve (PARTNER) Trial Cohort A. Circulation 2013;128:2776-84.
Nombela-Franco L, Eltchaninoff H, Zahn R, et al. Clinical impact and evolution of mitral regurgitation following transcatheter aortic valve replacement: a meta-analysis. Heart 2015;101:1395-405.
Kiramijyan S, Koifman E, Asch FM, et al. Impact of Functional Versus Organic Baseline Mitral Regurgitation on Short- and Long-Term Outcomes After Transcatheter Aortic Valve Replacement. Am J Cardiol 2016;117:839-46.
Toggweiler S, Boone RH, Rodés-Cabau J, et al. Transcatheter aortic valve replacement: outcomes of patients with moderate or severe mitral regurgitation. J Am Coll Cardiol 2012;59:2068-74.
Bedogni F, Latib A, De Marco F, et al. Interplay between mitral regurgitation and transcatheter aortic valve replacement with the CoreValve Revalving System: a multicenter registry. Circulation 2013;128:2145-53.
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