Wierzbowska-Drabik, K

Abstract Background The functional significance of the left ventricular (LV) hypercontractile phenotype (HP) in hypertrophic cardiomyopathy (HCM) remains unclear. Purpose To assess the systemic and coronary hemodynamic correlates of HP in HCM. Methods We enrolled 1533 HCM patients (age 51 ± 15 years, 965 males, 63%) with ejection fraction (EF) ≥50%, referred for rest transthoracic echocardiography (TTE) in 27 laboratories from 13 countries. Two-dimensional volumetric TTE assessment included LV outflow tract gradient (LVOTG), end-diastolic volume (EDV), end-systolic volume (ESV), EF, and LV force (systolic blood pressure + LVOTG/ESV, mmHg/mL). Coronary flow velocity in the mid-distal left anterior descending (LAD) coronary artery was assessed in 325 patients. HP was defined as the highest quartile of the force (> 7.32 mmHg/ml). Results Force was moderately related to EF (r = 0.48, p < 0.0001) and weakly to LVOTG (r = 0.36, p < 0.0001). Compared to non-HP patients, HP showed higher heart rate (72 ± 14 vs 67 ± 14 beats per minute, p <0.0001), lower stroke volume (50 ± 22 vs 67 ± 22 ml, p < 0.0001), larger left atrial volume index (44 ± 16 vs 40 ± 16 ml/m2, p = 0.011) and higher coronary flow velocity in the LAD (n = 325, 41 ± 12 vs 37 ± 14 cm/s, p = 0.021), see Figure. Abnormal B-lines (≥ 2) were present in 11 of the 39 HP compared to 39 of the 271 non-HP patients (28% vs 14 %, p = 0.05). E/e’ ratio was higher in HP (n = 59) vs. non-HP (n = 571) patients (11 ± 5.4 vs 9.6 ± 4.2, p = 0.018). Conclusion In patients with HCM, preserved EF, and no history of coronary artery disease, HP identified by resting TTE with supernormal LV force was associated with an unfavorable systemic hemodynamic and coronary flow profile. Compared to non-HP HCM patients, the HP was characterized by reduced stroke volume, impaired diastolic function, and increased resting coronary flow velocity. HP may reflect inefficient myocardial mechanics, with disproportionate energy expenditure mirrored by higher resting coronary flow despite reduced stroke volume generation, ultimately contributing to adverse remodeling and worse prognosisNon-HP vs HP LAVI and coronary LAD flow

Abstract Background Obese patients often exhibit a clustering of cardiovascular risk factors and are frequently referred for noninvasive cardiac imaging. Coronary microvascular dysfunction (CMD) represents an early indicator of cardiovascular disease that can be noninvasively diagnosed using coronary flow velocity reserve (CFVR) measurements obtained during stress echocardiography (SE) in patients without evidence of obstructive coronary artery disease (CAD). Purpose This study aimed to evaluate the prognostic significance of CFVR in overweight and obese patients within a prospective multicenter cohort. Methods 2273 patients (mean age 65 ± 11 years; 51% women) classified as overweight or obese (for definition see Table) were included in 27 sites from 11 countries. All patients had normal left ventricular ejection fraction (EF ≥ 50%), no prior history of CAD, and underwent exercise or pharmacological SE, which was negative for inducible ischemia. CFVR of the left anterior descending coronary artery was assessed, with CMD defined as CFVR >2.0. Patients were divided into two groups based on the presence (Group 1) or absence (Group 2) of CMD. The primary endpoint was overall mortality. Results CMD was identified in 492 patients (22%), with a mean CFVR of 2.3 ± 0.5 across the study population. Group 1 patients (CMD) were older, with a greater prevalence of diabetes and metabolic syndrome compared to group 2 (no CMD) (Table). During a median follow-up period of 2.1 years (IQR: 1.2-3.7 years), 103 patients (5%) died. Patients with CMD had significantly worse late survival compared to those without CMD (3-year survival: 96 ± 1% vs. 96 ± 1%, p=ns; 6-year survival: 79 ± 4% vs. 93 ± 1%, p < 0.0001): see Figure. Multivariate analysis adjusting for age, sex, EF, body mass index, smoking habits, diabetes, dyslipidemia, arterial hypertension, and type of stress confirmed CMD as an independent predictor of mortality (hazard ratio: 1.8 [95% CI: 1.1–2.8], p = 0.01). Conclusions CMD, assessed via CFVR during SE, was a robust and independent prognostic marker of long-term mortality in obese patients with preserved EF and no evidence of inducible ischemia. These findings underscore the pivotal role of noninvasive assessment of CMD in refining risk stratification and guiding clinical decision-making in this high-risk population.