Clinical Significance of Postoperative Atrial Fibrillation in Hypertrophic Cardiomyopathy Patients Undergoing Septal Myectomy.

BACKGROUND: The optimal management of hypertrophic cardiomyopathy (HCM) patients with postoperative atrial fibrillation (POAF) after surgical myectomy remains unknown. We sought to investigate the association between POAF and atrial fibrillation (AF) or cardioembolic events during follow-up to bridge this gap. METHODS: Patients undergoing surgical myectomy at 2 HCM referral centres in North America from 2002 to 2020 were included in this study. Patients with preoperative AF were excluded. POAF was defined as any episode of AF within 30 days after surgery. RESULTS: Of 1176 patients, 375 (31.9%) had POAF. Age (adjusted hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.03-1.06; P < 0.001), premyectomy left atrial diameter (LAD; adjusted HR 1.6, 95% CI 1.32-2.02; P < 0.001), and smoking (adjusted HR 1.60, 95% CI 1.17-2.20; P = 0.001) were associated with POAF on multivariable analysis. Of 934 patients with follow-up data, of duration 4.3 ± 4.1 years, AF was detected in 86 (9.2%). Only POAF (HR 4.20, 95% CI 2.44-7.23; P < 0.001), previous history of stroke (HR 4.81, 95% CI 1.63-14.17; P = 0.01), and postmyectomy LAD (HR 1.80, 95% CI 1.21-2.70; P = 0.004) were associated with AF incidence during follow-up. Cardioembolic events occurred in only 15 patients (1.6%). POAF was not associated with increased cardioembolic risk, with only 3 patients with POAF suffering such an event, all more than 4 years after surgery. CONCLUSIONS: POAF is common in HCM patients undergoing myectomy and is a predictor of AF during follow-up. Over long-term follow-up, cardioembolic events are uncommon. These findings suggest that routine long-term anticoagulation for all HCM patients with postmyectomy AF is not justified after the initial postoperative period.

Clinical Characteristics and Prognostic Importance of Left Ventricular Apical Aneurysms in Hypertrophic Cardiomyopathy.

BACKGROUND: Left ventricular (LV) apical aneurysms in hypertrophic cardiomyopathy (HCM) are a recognized risk marker for adverse cardiovascular events. There is variable practice among clinicians and discordance between international guidelines regarding treatment recommendations and prognostication for this important phenotype. OBJECTIVES: The authors sought to describe the morphology, clinical course, and risk of adverse events in a large single-center cohort of HCM patients with LV apical aneurysms. METHODS: This study analyzed 160 HCM patients with an LV apical aneurysm who were evaluated in our dedicated HCM clinic between January 1997 and April 2021. RESULTS: Mean age was 59.1 ± 13.6 years, and 71% of these patients were male. Mean aneurysm size was 1.77 ± 1.04 cm. Over 6.2 ± 4.8 years, 14 (9%) patients had a sudden cardiac death (SCD) event, including appropriate therapy from an implantable cardioverter-defibrillator (ICD) or resuscitation from cardiac arrest (annualized event rate 1.77%/y), 39 (24%) had either a thromboembolic stroke or apical thrombus formation (2.9%/y), and 14 (9%) developed LV systolic dysfunction with an ejection fraction (EF) <50% (1.28%/y). HRs for SCD, stroke or thrombus, and EF <50% per 1-cm increase in aneurysm size were 1.69 (P = 0.007), 1.60 (P = 0.0002), and 1.63 (P = 0.01), respectively. Aneurysm size ≥2 cm was associated with a 5-year SCD rate of 9.7%, compared with 2.9% for aneurysm size <2 cm (log-rank P = 0.037). This subgroup also had higher risk of stroke/thrombus formation (HR: 2.20; P = 0.002), with an annualized event rate of 2.7%/year. A total of 39 (24%) patients reached the combined end point of SCD, stroke, or LV dysfunction (2.12%/y) with an HR of 1.47/cm increase in aneurysm size (P = 0.003) and an HR of 2.22 for patients with aneurysm size ≥2 cm (P = 0.02). CONCLUSIONS: Increasing aneurysm size confers poorer prognosis. Aneurysm size ≥2 cm should alert potential consideration for prophylactic anticoagulation and primary prevention ICDs.

Left Ventricular Apical Aneurysms in Hypertrophic Cardiomyopathy: Equivalent Detection by Magnetic Resonance Imaging and Contrast Echocardiography.

BACKGROUND: Left ventricular (LV) apical aneurysm is a unique morphological entity and novel adverse risk marker existing within the broad phenotypic spectrum of hypertrophic cardiomyopathy (HCM). Its true prevalence in the HCM population is likely underestimated because of inherent limitations of conventional noncontrast echocardiography. The authors hypothesized that contrast echocardiography is a reliable imaging technique compared with cardiovascular magnetic resonance (CMR) for the detection of apical aneurysms. The aim of this study was to assess the effectiveness of contrast echocardiography in the detection of LV apical aneurysms in patients with HCM in comparison with the gold standard, CMR. METHODS: One hundred twelve patients with HCM identified from an institutional clinical database, who underwent echocardiographic and CMR examinations within 12 months and had LV apical aneurysms identified on either or both imaging modalities, were retrospectively analyzed. Discordant cases were reviewed by an expert panel, and a consensus was reached regarding the presence or absence of an apical aneurysm. The reason for any discrepancy was recorded. RESULTS: The mean age of the patients was 59 ± 13 years, and 73% were men. Sixty-four (57%) underwent contrast echocardiography. The median interval between echocardiography and CMR was 118 days (interquartile range, 61-237 days). Thirty-nine patients (35%) had discordance between echocardiographic and CMR findings, of whom 20 had aneurysms reported on echocardiography but not CMR and 19 vice versa. Upon reanalysis by the expert panel, aneurysms were initially missed on CMR in 16 patients (80%), largely because of interpretation error secondary to small aneurysms, with a mean aneurysm size of 0.82 ± 0.38 cm in these cases. Before secondary review by the expert panel, contrast echocardiography had sensitivity of 97% compared with 85% for CMR (P = .0198) and 64% for noncontrast echocardiography (P = .0001). After secondary review, contrast echocardiography had sensitivity of 98% compared with 67% for noncontrast echocardiography (P = .0001) and 97% for CMR (P = 1.00). CONCLUSIONS: Contrast echocardiography has high sensitivity for detecting LV apical aneurysms and should be used routinely in the evaluation and risk stratification of patients with HCM.