1

Case

An 84-year-old female was referred for transcatheter aortic valve replacement (TAVR) for severe symptomatic aortic stenosis (AS) and high operative risk. Her other past medical history included carotid artery disease, hypertension, dyslipidemia, diabetes with chronic non-healing lower extremity ulcers and coronary artery disease with triple vessel bypass surgery 20 years ago. Left ventricular ejection fraction was 55% by echocardiogram with mean gradient of 37 mm Hg across aortic valve and calculated aortic valve area of 0.6 cm ² . Coronary angiography revealed chronic total occlusions of right coronary (RCA), left anterior descending (LAD) and left circumflex arteries; left internal mammary graft to mid-LAD was widely patent with distal LAD providing robust epicardial collateral circulation (at the level of apex) to distal RCA ( Fig. 1 A–C , Supplementary Video 1 ). Transapical approach was chosen for TAVR considering an unsuitable bilateral transfemoral access secondary to severe peripheral arterial atherosclerosis and difficult anatomy for alternative routes. Apex was prepared in a traditional, standardized manner. Manual palpation was utilized to avoid nicking epicardial collaterals and standardized transapical technique was employed. She underwent uncomplicated deployment of 23 mm SAPIEN XT aortic valve. ( Fig. 1 D). She remained vasopressor dependent in the immediate post op period and was transferred to intensive care. Post-op electrocardiogram revealed inferolateral and lateral subendocardial injury ( Fig. 2 ). Cardiac troponin-T peaked at 8.9 ng/ml. Repeat echocardiogram revealed new moderate area of inferior and inferolateral akinesis and worsened eccentric mitral regurgitation ( Supplementary Video 2 ). With rapidly progressing renal failure and with no viable percutaneous option, cardiac catheterization and mechanical circulatory support were not performed. The patient was made comfort care based on family’s wishes. Likely cause of the patient’s infarction was ligation of the apical LAD to distal RCA epicardial collaterals as a result of pledgetted suturing and consequent myocardial infarction. The patient rapidly progressed to cardiogenic shock with worsening multi-organ failure and expired.

Coronary angiography showing severe native coronary artery disease with apical collateralization and transapical aortic valve replacement. (A, B) Native left coronary angiogram showing chronic total occlusions of right coronary artery (RCA), left anterior descending (LAD) and left circumflex arteries with a patent ramus intermedius branch providing moderate collaterals to obtuse marginal artery. (C) Left internal mammary artery (LIMA) graft injection showing widely patent to LIMA graft with distal LAD providing robust epicardial collateral circulation to distal RCA at apex. (D) Successful trans-apical deployment of 23 mm SAPIEN aortic valve.

Comparison of baseline (A) and post trans-apical trans-catheter aortic valve replacement (B) electrocardiograms.

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Discussion

Since FDA’s approval of TAVR for severe AS in high risk patients in late 2011, the number of centers performing TAVR in United States has more than doubled . Recently, Carrol et al. reported improved TAVR outcomes for centers with higher procedure volume with fewer complications even after adjusting for individual risk factors from current TVT/STS registry data . Even so, despite current advances in technique, experience and miniaturization of deployment systems, individual patient risk factors remain pivotal in predicting long-term outcomes. As in our case, history of prior coronary bypass grafting (CABG) operation remains a key element in overall risk stratification of patients with severe AS, significantly increasing their risk of perioperative mortality and morbidity .

A multidisciplinary team approach involving the cardiac surgeon, interventional cardiologist and preprocedural imaging evaluation remains paramount in achieve best procedural outcomes . Access routes for TAVR are carefully reviewed in valve team meetings preoperatively and individualized based on patient’s vascular anatomy and other comorbidities. Trans-apical approach is commonly utilized in patients with prior CABG and concomitant severe peripheral vascular disease, as in our case, with similar success rates compared to trans-femoral approach . Direct-aortic approach, although associated with higher risk of open surgical conversion and need for blood transfusions, can also be considered as an alternative strategy with similar one year outcomes compared to trans-apical access in patients with non-favorable iliofemoral access . However, this was avoided in our case owing to the presence of non-healing diabetic ulcers, poses a higher wound infection risk with hemi-sternotomy which is required as a part of direct-aortic approach. Trans-subclavian access is best avoided in patients with a patent in situ left internal mammary artery (LIMA) graft, significant tortuosity or a diameter < 7 mm , which again in our case was 6 mm and short. Lastly, trans-caval route, which could have been considered with the aid of a proctor, was not considered due to lack of local expertise/experience at the time procedure was conducted.

Trans-apical approach, which was chosen for the case, poses its own challenges in patients with prior cardiac surgery with frequent presence of pericardial adhesions, making it more difficult to identify key anatomical landmarks including left anterior descending artery (LAD) . A peri-procedural multi-image modality approach is recommended to obtain correct angle of entry into a desired “window of safety”—lateral segment of the apex away from LAD artery and lung tissue. This is usually achieved by placing a radiopaque marker, such as a hemostat under echocardiographic guidance in preselected intercostal space from pre-procedural CT-scans and adjusting angle for intended trajectory of puncture under fluoroscopy or preferably CTA-fluoroscopy fusion guidance technique . As proposed by Maluenda et al. this can be further facilitated by simultaneous angiography of left internal mammary artery bypass or native LAD (where flow exists), to confirm apical location of LAD and aid in proper angulation for the apical needle puncture. In the hindsight, utilizing this technique could have prevented the possible injury to the LAD and nicking of epicardial collateral circulation, which in our case was providing circulation to the inferior and posterior myocardium.

With an increasing popularity and availability of TAVR, it is important for physicians to recognize the fine line between utility and futility of the procedure. This becomes less so evident in high risk surgically inoperable patients who fall in the gray zone. It is important to recognize other nonconventional risk factors, like risk of damage to epicardial collateral circulation as in our case, which may render the procedure futile in the absence of other surgical/percutaneous options. As recommended by Lindman et al. such decisions should be made in a multidisciplinary heart valve team approach taking into account patient preferences, goals and values recognizing that futility is a professional judgment that takes over patient autonomy . Moreover, it is important for the physician, patient and the family to remain realistic about clinical prognosis and chances of procedure related adverse outcomes.