Ommen, Steve R.

Abstract Background Hypertrophic cardiomyopathy (HCM) is a heritable cardiac disorder characterized by increased left ventricular (LV) wall thickness, often leading to heart failure (HF). The role of cardiovascular magnetic resonance (CMR) imaging in predicting new onset of HF symptoms in patients with HCM remains unknown. This study aimed to identify CMR predictors of new-onset HF symptoms in individuals with HCM. Methods This study was a single-centre retrospective cohort study of HCM patients treated at a tertiary referral centre in the USA who underwent CMR examination between 1998 and 2018, had no HF symptoms at baseline CMR, and at least 1 year of follow-up. Clinical data were collected by review of electronic medical records, and CMR images were analyzed by a blinded expert cardiac radiologis. The primary outcome was new onset of HF symptoms, defined as New York Heart Association (NYHA) class ≥ II at follow-up. Kaplan–Meier analyses and Cox proportional hazard analyses were performed. Results Of 1462 patients diagnosed with HCM who had at least 1 CMR, 276 HCM patients without HF symptoms (average age 52.7 years, 33.3% female),median maximum left ventricular (LV) wall thickness was 19 mm ([IQR] 17–22) with a and median LV ejection fraction of 71% (IQR 66–77). Late gadolinium enhancement was detected in 56.2%) patients (60.7% had mild; 30.7% moderate; 8.6% severe). During a median follow-up period of 6.3 years, 93 patients developed HF symptoms (NYHA class II in 56 (60.2%); class III in 31 (33.3%); and class IV in 6 (6.5%). Multivariable analysis adjusted for age showed that LA enlargement (HR 1.626; 95% CI 1.01–2.62; P = .045) and LV mass index (HR 1.014; 95% CI 1.007–1.022; P≤ .001) and sex (HR 1.7; 95% CI 1.074–2.691; P = .023) were independent predictors of new onset of HF symptoms in patients with HCM. Conclusions Nearly half of the patients with HCM developed HF symptoms within 6.3 years. Left atrial enlargement, LV mass index, and sex were independent predictors of new onset of HF symptoms in HCM patients. These findings emphasize the value of CMR in HF risk stratification.

Abstract Aims Obesity is linked with worse outcomes in hypertrophic cardiomyopathy (HCM). While both bariatric surgery (BS) and GLP-1 receptor agonists (GLP-1RA) promote weight loss and may improve cardiometabolic risk, their comparative outcomes in HCM remain unclear. Methods and results Adults with HCM and body mass index (BMI) ≥ 30 kg/m were divided into two cohorts: (i) GLP-1 RA users who never had BS, and (ii) BS patients who never received GLP-1 RA. Propensity score matching (1:1) was performed to balance demographics, comorbidities, and medications. Outcomes over 24 months include all-cause mortality, acute heart failure (HF) hospitalization, arrhythmias, change in BMI, and cardiovascular symptoms. Hazard ratios with 95% confidence intervals were estimated using Cox models. Of 5002 patients, 955 were included in each matched cohort after matching (mean age 54 ± 13 years, 70% female, BMI 40.0 kg/m). GLP-1 RA was associated with a significantly lower observed rate of all-cause mortality compared with BS (2.0% vs. 4.4%; HR 0.46; 95% CI 0.27–0.80; P = 0.004) and HF hospitalization (8.7% vs. 14.0%; HR 0.60; 95% CI 0.46–0.79; P < 0.001). Similarly, GLP-1 RA use was associated with a lower incidence of composite cardiovascular outcomes (10.7% vs. 17.2%; HR 0.60; 95% CI 0.47–0.77; P < 0.001). Rates of arrhythmia and cardiovascular symptoms were comparable between the two groups. BMI reduction was greater after bariatric surgery (−4.0 vs. −2.6 kg/m; P < 0.001). Conclusion In obese patients with HCM, GLP-1 RA therapy was associated with lower all-cause mortality and fewer HF events compared with BS. Future studies are warranted to confirm our findings.

Once considered rare and essentially untreatable with a grim prognosis and reduced life expectancy, hypertrophic cardiomyopathy (HCM) has evolved substantially over 6 decades. Ultimately, HCM has become a contemporary global disease with pharmacologic and interventional options offering effective personalized treatment for all adverse disease pathways. Striking reduction in HCM‐related mortality to ≤0.5%/year in optimally treated cohorts is now comparable to that expected in the US general population, lower than most other disease risks to living, and 10‐fold less than the earliest estimates. The few deaths directly related to HCM are now largely attributable to advanced (end‐stage) heart failure in patients with nonobstructive HCM. Determinants of this transformation to a lower risk disease are evident in hallmark clinical inflection points and breakthroughs, including dedicated HCM programs assembling large clinical databases in which focused (and unfunded) physician‐investigators have derived data directly from patients in clinical practice. Evidence‐based observational studies report emergence of contemporary treatment strategies enhancing survival: implantable defibrillators prevent arrhythmic sudden death globally with 95% sensitive patient selection using an American Heart Association/American College Cardiology risk stratification algorithm; low‐risk, high‐benefit surgical myectomy reverses outflow obstruction and heart failure in >90% with a long‐term survival benefit; and aggressive anticoagulation has reduced embolic strokes. Recent novel pharmacologic alternatives (cardiac myosin inhibitors) are proving effective in relieving obstruction/symptom burden and changing disease management. These principles and time‐tested patient‐centered research strategies uniquely tailored to the heterogeneous HCM clinical spectrum are pivotal in providing practice insights, offering a vulnerable population more optimistic prognosis including opportunity to achieve normal longevity not available to prior generations of patients.

ABSTRACT Introduction Cardiac myosin inhibitors (CMIs) improve hemodynamics and symptoms in hypertrophic cardiomyopathy (HCM), but recent real‐world data have raised concerns regarding an increased risk of atrial fibrillation (AF). We sought to reassess AF risk using randomized controlled trial (RCT) evidence and to contextualize discrepancies with observational reports. Methods and Results We performed a systematic review and random‐effects meta‐analysis of RCTs evaluating the effect of CMIs on incident AF in HCM. MEDLINE, Scopus, and CENTRAL were searched through November 25, 2025. Eight RCTs ( n = 1581) comparing mavacamten or aficamten with placebo or active control were included. Event counts were pooled as risk ratios (RRs) with 95% confidence intervals (CIs). CMIs were not associated with increased AF risk (RR 1.11, 95% CI 0.62–1.98; heterogeneity I 2 = 0%). No differences were observed between mavacamten and aficamten, with consistent findings across HCM subtypes (obstructive and non‐obstructive). Importantly, most trials (7/8) excluded patients with uncontrolled, persistent, or permanent AF, five excluded paroxysmal AF at screening, and one excluded any AF history. Baseline left atrial enlargement was generally in the mild to moderate range across trials, suggesting limited representation of high‐risk AF phenotypes. Conclusion Randomized evidence to date does not demonstrate an increased AF risk with CMIs. Differences between RCT populations and real‐world cohorts, including restrictive AF eligibility criteria, lower baseline atrial remodeling, and limited rhythm surveillance may explain discordant observational findings and highlight the need for longitudinal monitoring in clinical practice.

ABSTRACTBackgroundLate gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging is a well‐established indicator of myocardial fibrosis in hypertrophic cardiomyopathy (HCM). However, its association with electrocardiographic (ECG) abnormalities and the risk of atrial fibrillation (AF) remains uncertain.ObjectivesTo investigate the association between the presence and burden of LGE with ECG characteristics, including precordial voltage, depolarization and repolarization abnormalities, and the incidence of AF in adults with HCM.MethodsWe conducted a retrospective cohort study of 144 adults with HCM with CMR and 12‐lead ECG within 30 days of each other. LGE was quantified as a percentage of LV mass and categorized as absent, < 5%, or ≥ 5%. ECG parameters, including QRS voltage, repolarization abnormalities, and LVH criteria, were analyzed. Incident AF was assessed during a median follow‐up of 6.6 years.ResultsLGE was present in 96 (67%) patients, with 21 (22%) having ≥ 5% LGE. There were no significant differences in precordial voltage between patients with and without LGE across Sokolow‐Lyon, Cornell, and Romhilt‐Estes criteria. However, T‐wave inversion was more common in leads I (41% vs. 19%, p = 0.009), aVL (50% vs. 31%, p = 0.033), and V4 (41% vs. 23%, p = 0.035) in patients with LGE. Patients with ≥ 5% LGE had a significantly lower median LVEF (64% vs. 74%, p = 0.003). Additionally, LGE presence was not associated with an increased risk of incident AF (HR 1.8, 95% CI 0.6–5.3, p = 0.308).ConclusionIn contrast to pediatric HCM, LGE is associated with specific ECG repolarization abnormalities, particularly T‐wave inversion in lateral leads, but does not significantly affect precordial voltage in adults.

Abstract Aims Significant advancements have been made in the management of obstructive hypertrophic cardiomyopathy (oHCM), yet the extent of left ventricular outflow tract (LVOT) gradient reduction achieved with commonly used pharmacological therapies [beta-blockers (BBs), calcium channel blockers (CCBs), disopyramide, and cardiac myosin inhibitors (CMIs)] relative to each other is still unclear. Methods and results PubMed and Scopus were searched up to September 2024. Clinical trials or observational studies that assessed the changes associated with BBs, CCBs, disopyramide, or CMIs in LVOT gradient at rest or with provocation in patients with oHCM were included. Mean changes in LVOT gradients were pooled as mean differences (MD) with 95% confidence intervals (CIs) in a random-effects model. Thirty-seven studies, with 44 arms and 1898 patients, were included in the analysis. At the therapeutic class level, pooled analysis showed that disopyramide was associated with the highest reduction in LVOT gradient at rest [MD: −43.5 (95% CI, −51.6 to −35.3)], followed by CMIs [MD: −34.8 (95% CI, −40.6 to −29.0)], BBs [MD: −20.7 (95% CI, −29.4 to −12.0)], and then CCBs [MD: −14.7 (95% CI, −23.3 to −6.1)], inter-action P &lt; 0.01. Within CMIs, mavacamten had a higher effect than aficamten on gradient reduction; among the included BBs, metoprolol showed the highest gradient reduction, while among CCBs, verapamil was the most effective (inter-action P &lt; 0.01). Similar results were observed for provocable LVOT gradients. Conclusion Pharmacological therapies effectively reduced LVOT gradients in oHCM patients to varying degrees, with disopyramide and CMIs showing the highest effect, followed by BBs and CCBs.

Background: Hypertrophic cardiomyopathy (HCM) is a genetic cardiomyopathy marked by increased left ventricular wall thickness, leading in some cases to left ventricular outflow tract (LVOT) obstruction, heart failure, and arrhythmias. Mavacamten, a selective allosteric inhibitor of cardiac myosin, has demonstrated benefits in improving hemodynamics and reducing LVOT obstruction. However, its impact on arrhythmic burden remains unclear, with reports of early atrial fibrillation (AF) risk contrasting with long-term reductions in arrhythmias. This study assesses the temporal patterns of Holter-detected arrhythmias in HCM patients treated with mavacamten. Methods: This retrospective study included HCM patients from three Mayo Clinic sites. Baseline demographic, clinical, and echocardiographic data were collected. Holter monitoring was performed at baseline, short-term (<6 months), and long-term (>6 months) follow-up. Arrhythmic events, including premature atrial contractions (PACs), premature ventricular contractions (PVCs), and supraventricular tachycardia (SVT), were analyzed using standardized rates per 24 h. Statistical comparisons utilized the Wilcoxon signed-rank test. Results: Twenty-seven patients (56% female, median age 66 years) were included. PACs, PVCs, and SVT duration transiently but not significantly increased at short-term follow-up but returned to baseline at long-term follow-up. No sustained or high-risk ventricular arrhythmias were observed. Conclusions: Mavacamten is associated with transient arrhythmic fluctuations early in treatment, followed by stabilization. These findings support its long-term electrophysiological safety and underscore the need for early rhythm monitoring. Further research should explore its role in arrhythmic risk stratification in HCM patients.