Left ventricular elastance with resting volumetric transthoracic echocardiography identifies different phenotypes in heart failure with preserved ejection fraction
Abstract Background Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous entity including patients with different phenotypes of near normal, normal, and supernormal left ventricular (LV) function. Objectives To assess the value of resting LV elastance (also known as force) with transthoracic echocardiography (TTE) to identify HFpEF phenotypes. Methods In a prospective, observational, multicenter study, 2380 HFpEF patients were recruited from July 2016 to May 2024. Systolic blood pressure (SBP) was measured. We assessed LV end-diastolic volume (EDV), end-systolic volume (ESV), EF, force (SBP/ESV), stroke volume (SV), arterial elastance (AE), ventricular-arterial coupling (VAC), and left atrial volume index (LAVI). Global longitudinal strain (GLS) was available in 1164 (48.9%) patients. 680 patients finished follow-up with a composite end-point of major adverse cardiac events (MACEs). Patients were divided into three groups: low force (< 25th percentile, Group 1, < 3.24 mmHg/ml), intermediate force (≥ 25th percentile and ≤ 75 thpercentile, Group 2, 3.24-5.48 mmHg/ml), and high force (> 75 th percentile, Group 3, >5.48 mmHg/ml). Results The 3 groups showed a gradient with descending values (Group 3>2>1) for SBP, EF, GLS, AE, and VAC, with the opposite gradient (Group 1> 2> 3) for EDV, ESV, SV, and LAVI values (all P<0.01). After a median follow-up of 16 months, 205 MACEs occurred in 138 patients. Cumulative MACEs rate was lowest in group 2 (14.7% person-year), higher in group 1 (16.1% person-year) and 3 (22.9% person-year, log rank p = 0.036). Conclusions HFpEF patients present with different LV contractile phenotypes, easily identified with resting LV force and volumetric TTE. The dominant hemodynamic feature of hypocontractile phenotype is a preload recruitment with larger LV EDV and normal SV, while the hypercontractile phenotype is characterized by a small LV with reduced SV. The hypercontractile and hypocontractile phenotypes are associated with a higher risk of subsequent events.
Functional reserve and prognosis in hypercontractile phenotype patients with heart failure and preserved ejection fraction
Abstract Backgrounds Transthoracic echocardiography (TTE) identifies a peculiar hypercontractile phenotype (HP) in patients with heart failure and preserved ejection fraction (HFpEF) with high resting left ventricular (LV) elastance (also called force). Objectives To assess the functional response and its prognosis associated with HP in HFpEF by stress echocardiography (SE). Methods In a prospective, observational, multicenter study, 1213 patients with HFpEF were divided into two groups based on the highest quartile of rest force: non-hypercontractile phenotype group (non-HP, < 5.64 mmHg/mL, Group 1, n= 910), and HP group (≥5.64 mmHg/mL, Group 2, n= 303). All patients underwent SE with at least 4 of the following stress parameters assessed: wall motion score index (WMSI), B-lines (4-site score), force-based LV contractile reserve, coronary flow velocity reserve (CFVR), and heart rate reserve (HRR). The employed stress was exercise (n=687), dobutamine (n=195), or vasodilators (n=331). SE score ranged from 0 (all steps normal) to 1-5, according to the number of abnormal steps. Follow-up was completed in a subset of 260 patients. Results The 2 groups showed similar values of peak stress WMSI but the global functional burden was higher in Group 2 patients: see table. In a subset of 260 patients who finished follow-up, there were 212 non-HP patients and 48 HP patients. During a median follow-up of 15 months (interquartile range: 10-20), 26 deaths, 20 heart failure (HF) rehospitalizations, and 64 major adverse cardiovascular events (MACEs) occurred. The cumulative HF rehospitalization rate and MACEs rate were higher in HP group (log-rank p<0.01): see figure. Rest force (HR, 1.17; 95% CI: 1.06-1.29; P: 0.040), rest SPAP (HR, 1.08; 95% CI: 1.02-1.14; P: 0.007) and ABCDE score (HR, 1.15; 95% CI: 1.01-1.66; P: 0.032) were independently associated with MACEs. Conclusions HFpEF patients with HP are functionally weaker with multiple vulnerabilities during stress and at higher risk of subsequent events compared to non-HP patients.Relation between resting values of force