Abstract Background Exercise stress echocardiography (ESE) is recommended in patients with mitral regurgitation (MR) when resting echocardiographic findings and symptoms do not align. However, the role of MR assessment in patients undergoing ESE for any indication remains uncertain. Purpose This study aimed to investigate whether the assessment of MR during ESE provides prognostic value beyond the evaluation of inducible regional wall motion abnormalities (RWMA) in patients undergoing ESE for any clinical indication, including suspected coronary artery disease (CAD). Methods Data were analyzed from a large multicenter and multinational prospective study. Current analysis included patients who underwent ESE for any indication and had MR (from 0= absent, to 3= severe) assessed at rest and peak exercise with an integrated qualitative, semi-quantitative, and (in selected cases) quantitative assessment. The primary endpoint was all-cause mortality. Results Of 1,351 included patients (age 56±16 years; 66% women; 30% with known CAD). MR score increased during exercise (rest=0.74±0.7 vs. peak=0.89±0.8, p<0.001), with severe MR present in 2% of patients at rest and 7% at peak ESE. Patients with severe MR during exercise (n=96, Group 1) compared to those with non-severe MR during exercise (n=1255, Group 2) showed more B-lines, lower left ventricular contractile and chronotropic reserve, and trend (p=0.09) to more frequent decrease in ejection fraction during ESE (Table 1). After a median follow-up of 2.1 years (IQR 1.0–6.9), 99 patients (7%) had died. Severe MR at rest was associated with increased mortality (log-rank p<0.001). Patients with severe MR at peak ESE had a higher risk of death compared to the other patients (log-rank p 0.035) (Figure 1). After adjusting for age, CAD, and inducible RWMA, severe MR with exercise remained strongly associated with an increased risk of death (adjusted-HR: 2.2, 95%CI 1.3-3.8, p=0.002). Similar results were seen with further adjustment for rest MR severity (adjusted-HR:1.9, 95%CI 1.02-3.5, p=0.004). Conclusion Patients, with and without CAD, with severe MR during ESE have greater functional impairment expressed by more pulmonary congestion, blunted heart rate reserve, and lower left ventricular contractile reserve. The assessment of MR during ESE provides significant prognostic information, independent of resting RWMA or inducible ischemia. Incorporating MR evaluation into routine ESE protocols may improve clinical decision-making and patient outcomes.Fig 1 Survival by MR at peak exercise Table 1
Chronotropic incompetence during exercise or pharmacological stress is associated with survival in patients with chronic coronary syndromes
Abstract Background Chronotropic incompetence (CI) is a biomarker of cardiac autonomic dysfunction. Aim To assess the risk stratification value of CI during physical or pharmacological stress echocardiography in patients with chronic coronary syndromes. Methods In a prospective, multicenter, international, observational study design, we enrolled 13,445 patients with known or suspected chronic coronary syndromes who underwent stress echo in 19 sites from 10 countries using either exercise (n=2,594), dobutamine (n=2,440), or dipyridamole (n=8,411). Heart rate was automatically measured from the 1-lead ECG in the echo monitor. We considered CI as failure to reach 85% of the maximal predicted (220-age) heart rate for exercise and dobutamine, and heart rate reserve (peak/rest heart rate) <1.22 (<1.17 in permanent atrial fibrillation) for dipyridamole. All-cause death was the outcome measure. Results Heart rate reserve was available in all patients; there was no extra imaging or analysis time, and no intra- and inter-observer variability. CI was observed in 5,045 patients (38%); abnormal regional wall motion abnormality in 1,648 (13%). Over a median follow-up time of 3.5 years, there were 2,426 (18%) deaths. The 10-year mortality was 39% in patients with and 21% in patients without CI (p<0.0001). CI was associated with a significant (p<0.0001) increase in 10-year mortality in all age groups ranging from <54 years to >75 years. In addition, it was associated with increased mortality (p<0.0001) irrespective of β-blocker use (Figure). Cox multivariable analysis revealed that CI was a significant predictor of mortality (HR 1.60, 95% confidence interval 1.47-1.74; p<0.0001) together with age, male sex, diabetes mellitus, ejection fraction, and resting heart rate. Conclusion In patients with chronic coronary syndromes, CI during physical or pharmacological stress is a simple, inexpensive, quantitative, and objective predictor of survival.
Hypercontractile phenotype in hypertrophic cardiomyopathy correlate with adverse systemic and coronary parameters
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
Prognostic value of coronary flow velocity reserve in obese patients with preserved ejection fraction and negative stress echocardiography
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.
Moderate ischemic mitral regurgitation at rest is associated with multiple functional vulnerabilities during stress echocardiography
Abstract Background Ischemic mitral regurgitation (IMR) is a common complication of coronary artery disease (CAD), often occurring after myocardial infarction (MI). Even when moderate in severity, IMR is associated with adverse outcomes, including a twofold increase in mortality rates. Aim To assess the functional correlates of resting IMR during stress echocardiography (SE) in patients with CAD. Methods This prospective multicenter study included 192 patients with CAD (143 males; mean age 65 ± 10 years) from eight cardiology institutions. Exclusion criteria included a history of coronary artery bypass surgery, more than moderate IMR, and other significant valvular diseases. Patients were divided into two groups based on semiquantitative- quantitative assessment at rest based on EACVI-ASE criteria: Group 1: Patients with moderate IMR, Group 2: Patients without IMR or with trivial IMR. All patients underwent stress echocardiography (SE) using the ABCE protocol. Patients underwent exercise tests, if execise echocardiography was not possible, dobutamine stress tests were performed. At rest and peak SE, we assessed: Left atrial volume index (LAVi), Left ventricular end-diastolic (LV EDV) and end-systolic volumes (LV ESV), ejection fraction (EF), wall motion score index (WMSI), global longitudinal strain (GLS), B-lines (4-site simplified scan), tricuspid annular plane systolic excursion (TAPSE), systolic pulmonary artery pressure (SPAP), LV contractile reserve (LVCR) and heart rate reserve (HRR). Results Despite similar EF at rest, Group 1 patients showed more pronounced functional impairment at rest, which increased during stress. Stress-induced functional worsening affected indices of MR (more frequently becoming severe), ischemic burden (WMSI), diastolic function (LAVI and LVEDV dilation), LV systolic function (LVCR), pulmonary congestion (B-lines), cardiac sympathetic reserve (reduced HRR) and right ventricular/pulmonary artery coupling (reduced TAPSE/SPAP): table 1. Conclusion Compared to CAD patients with absent-to-trivial resting IMR, patients with moderate IMR at rest show a constellation of functional vulnerabilities during SE involving more frequent exercise-induced worsening of MR, blunted LV diastolic and systolic reserve, more pulmonary congestion, impaired cardiac autonomic reserve, and worse right ventricular-pulmonary artery coupling. The individual patient's functional response heterogeneity can be identified with comprehensive exercise SE, possibly a roadmap to personalized and targeted therapeutic interventions.