Outcomes in Patients With Obstructive Hypertrophic Cardiomyopathy and Concomitant Aortic Stenosis Undergoing Surgical Myectomy and Aortic Valve Replacement

Case Report: Mechanical hemolysis resulting from left ventricular outflow tract obstruction after aortic valve replacement relieved by transapical beating-heart septal myectomy

Background

Aortic stenosis (AS) in combination with left ventricular outflow tract obstruction (LVOTO) has occasionally been reported. However, making a precise diagnosis and successfully treating this combination is challenging due to the hemodynamic interaction between the two conditions.

Case summary

A 56-year-old male patient who had been diagnosed with severe AS and asymmetric left ventricular hypertrophy underwent aortic valve replacement (AVR) and a conventional septal myectomy. Immediately after the procedure, significant systolic anterior motion and mitral regurgitation developed, necessitating a surgical mitral edge-to-edge repair. Ten days after the procedure, the patient developed hematuria and LVOTO, which was confirmed by echocardiography. Because the LVOTO might have been the cause of the hematuria, the patient underwent alcohol septal ablation, but this had little effect. Three months later, a transapical beating-heart septal myectomy (TA-BSM) was performed in our hospital. Postoperatively, the LVOTO had been significantly ameliorated and the hematuria had resolved.

Conclusion

For patients with AS and LVOTO due to a hypertrophic interventricular septum, inadequate amelioration of the LVOTO after AVR may lead to severe hemolytic hematuria. TA-BSM is a minimally invasive, safe, and effective surgical procedure for ameliorating LVOTO in patients with aortic valve prostheses.

Impact of concomitant surgical interventions on outcomes of septal myectomy in obstructive hypertrophic cardiomyopathy

BACKGROUND

Septal myectomy (SM) is offered to symptomatic patients with obstructive hypertrophic cardiomyopathy (oHCM) despite medical therapy. Frequently, patients undergo concomitant planned or ad-hoc mitral valve replacement (MVR), aortic valve replacement (SAVR), or coronary artery bypass grafting (CABG).

OBJECTIVES

We sought to assess characteristics and outcomes of patients with oHCM undergoing concomitant surgical interventions at the time of SM.

METHODS

The National Readmission Databases were used to identify all SM admissions in the United States (2010-2019). Patients undergoing SM were stratified into: isolated SM (±MV repair), SM + CABG only, SM + MVR, SM + SAVR, and SM + MVR + SAVR. Primary outcomes were in-hospital mortality, in-hospital adverse events, and 30-day readmission.

RESULTS

12,063 encounters of patients who underwent SM were included (56.1% isolated SM, 9.0% SM + CABG only, 17.5% SM + MVR, 13.1% SM + SAVR, and 4.3% SM + MVR + SAVR). Patients who underwent isolated SM were younger (54.3 vs. 67.1 years-old, p < 0.01) and had lower overall comorbidity burden. In-hospital mortality was lowest in isolated SM, followed by CABG only, SM + SAVR, SM + MVR, and SM + SAVR+MVR groups (2.3% vs. 3.7% vs. 5.3% vs. 6.7% vs. 13.7%, p < 0.01), respectively. SM with combined surgical interventions was associated with higher adverse in-hospital events (24.3% vs. 11.1%, p < 0.01) and 30-day readmissions (16.9% vs. 10.4%, p < 0.01). MV repair performed concomitantly with SM was not associated with increased in-hospital mortality (3.9% vs. 3.4%, p = 0.72; aOR 0.99; 95% CI: 0.54-1.80, p = 0.97]) or adverse clinical events.

CONCLUSIONS

In SM for oHCM, patients undergoing concomitant surgical interventions were characteristically distinct. Aside from MV repair, concomitant interventions were associated with worse in-hospital death, adverse in-hospital events, and 30-day readmission.

Treatment Strategies for Hypertrophic Cardiomyopathy: Alcohol Septal Ablation and Procedural Step-by-Step Technique

Alcohol septal ablation (ASA) is a well-established procedure for septal reduction therapy in patients with obstructive hypertrophic cardiomyopathy, significant at rest or provocable outflow tract gradients, and medically refractory symptoms. This percutaneous approach to relief of obstruction and eventual cardiac remodeling involves the infusion of a small quantity of ethanol into an appropriately targeted septal artery that is feeding the basal septum to create an iatrogenic and controlled focal infarction. Early akinesia is followed by subsequent thinning and remodeling, which widens the outflow tract, reducing or eliminating the obstruction. Historically, the use of ASA was reserved primarily for high-risk surgical candidates; however, more contemporary data suggest similar outcomes in the short-term and long-term safety of the procedure and overall effectiveness in relieving obstructive symptoms when it is performed in broader populations at experienced centers. Therefore, the current guidelines published in 2020 support ASA as a class 1 indication, similar to its open-heart surgical counterpart, surgical myectomy, when no concomitant significant coronary or valve surgical indication exists. This article summarizes contemporary management of patients with hypertrophic cardiomyopathy who were selected for ASA and details procedural methods and outcomes.

Endovascular Transcatheter Aortic Valve Replacement Outcomes in Hypertrophic Cardiomyopathy: Insights from the National Inpatient Sample (2014-2018)

BACKGROUND

Outcomes of patients with hypertrophic cardiomyopathy (HCM) following transcatheter aortic valve replacement (TAVR) remain largely unknown.

OBJECTIVES

This study sought to assess the clinical characteristics and outcomes of HCM patients following TAVR.

METHODS

We queried the National Inpatient Sample from 2014 to 2018 for TAVR hospitalizations with and without HCM, creating a propensity-matched cohort to compare outcomes.

RESULTS

207,880 patients that underwent TAVR during the study period, 810 (0.38%) had coexisting HCM. In the unmatched population, TAVR patients with HCM compared to those without HCM, were more likely to be female, had a higher prevalence of heart failure, obesity, cancer, and history of pacemaker/implantable cardioverter defibrillation, and were more likely to have nonelective and weekend admissions (p for all <0.05). TAVR patients without HCM had higher prevalence of coronary artery disease, prior percutaneous coronary intervention, prior coronary artery bypass grafting, and peripheral arterial disease compared to their counterparts (p for all <0.05). In the propensity-matched cohort, TAVR patients with HCM had significantly higher incidence of in-hospital mortality, acute kidney injury/hemodialysis, bleeding complications, vascular complications, permanent pacemaker requirement, aortic dissection, cardiogenic shock, and mechanical ventilation requirement.

CONCLUSION

Endovascular TAVR in HCM patients is associated with an increased incidence of in-hospital mortality and procedural complications.

Sex-Related Differences among Adults with Hypertrophic Obstructive Cardiomyopathy Undergoing Transcoronary Ablation of Septal Hypertrophy

(1) Background: The transcoronary ablation of septal hypertrophy (TASH) is an established therapy for hypertrophic obstructive cardiomyopathy (HOCM). Previous studies on this topic are characterised by a consistent male predominance and show a worse prognosis in females. (2) Methods: This study is a retrospective analysis of all TASH procedures conducted between 2006 and 2021 at a tertiary academic centre. A solution of 75 µm microspheres (Embozene^®, Boston Scientific, Marlborough, MA, USA) was used as an embolising agent. The outcomes of interest were left ventricular outflow tract (LVOT) gradient reduction and symptom improvement among males vs. that among females. Secondarily, we analysed the sex-related differences in procedural safety outcomes and mortality. (3) Results: The study population consisted of 76 patients, with a median age of 61 years. Females comprised 57% of the cohort. We observed no sex-related differences in the baseline LVOT gradients at rest or under provocation (p = 0.560 and p = 0.208, respectively). Females were significantly older at the time of the procedure (p < 0.001), had lower tricuspid annular systolic excursion (TAPSE) (p = 0.009), presented a worse clinical status according to the NYHA functional classification (for NYHA ≥ 3, p < 0.001), and were more often on diuretics (p < 0.001). We did not observe sex-related differences in absolute gradient reduction at rest (p = 0.147) and under provocation (p = 0.709). There was a reduction in the NYHA class by a median value of 1 (p = 0.636) at follow-up for both sexes. Postprocedural access site complications were documented in four cases (two of which concerned females), and complete atrioventricular block was noted in five patients (three of which concerned females). The 10-year survival rates were comparable between the sexes (85% in females and 88% in males). The female sex was not associated with enhanced mortality according to multivariate analysis after adjusting for the confounding variables (HR 0.94; 95% CI 0.376-2.350; p = 0.895), but we observed age-related differences in long-term mortality (HR 1.035; 95% CI 1.007-1.063; p = 0.015). (4) Conclusions: TASH is safe and effective in both sexes, irrespective of their clinical differences. Women present at an advanced age and with more severe symptoms. An advanced age at the time of the intervention is an independent predictor of mortality.