Feasibility and value of two-dimensional volumetric stress echocardiography.

BACKGROUND: Stroke volume response during stress is a major determinant of functional status in heart failure and can be measured by two-dimensional (2-D) volumetric stress echocardiography (SE). The present study hypothesis is that SE may identify mechanisms underlying the change in stroke volume by measuring preload reserve through end-diastolic volume (EDV) and left ventricular contractile reserve (LVCR) with systolic blood pressure and end-systolic volume (ESV). METHODS: We enrolled 4735 patients (age 63.6±11.3 years, 2800 male) referred to SE for known or suspected coronary artery disease (CAD) and/or heart failure (HF) in 21 SE laboratories in 8 countries. In addition to regional wall motion abnormalities (RWMA), force was measured at rest and peak stress as the ratio of systolic blood pressure by cuff sphygmomanometer/ESV by 2D with Simpson's or linear method. Abnormal values of LVCR (peak/rest) based on force were ≤1.10 for dipyridamole (N.=1992 patients) and adenosine (N.=18); ≤2.0 for exercise (N.=2087) or dobutamine (N.=638). RESULTS: Force-based LVCR was obtained in all 4735 patients. Lack of stroke volume increase during stress was due to either abnormal LVCR and/or blunted preload reserve, and 57% of patients with abnormal LVCR nevertheless showed increase in stroke volume. CONCLUSIONS: Volumetric SE is highly feasible with all stresses, and more frequently impaired in presence of ischemic RWMA, absence of viability and reduced coronary flow velocity reserve. It identifies an altered stroke volume response due to reduced preload and/or contractile reserve.

Lung Ultrasound and Pulmonary Congestion During Stress Echocardiography.

OBJECTIVES: The purpose of this study was to assess the functional and prognostic correlates of B-lines during stress echocardiography (SE). BACKGROUND: B-profile detected by lung ultrasound (LUS) is a sign of pulmonary congestion during SE. METHODS: The authors prospectively performed transthoracic echocardiography (TTE) and LUS in 2,145 patients referred for exercise (n = 1,012), vasodilator (n = 1,054), or dobutamine (n = 79) SE in 11 certified centers. B-lines were evaluated in a 4-site simplified scan (each site scored from 0: A-lines to 10: white lung for coalescing B-lines). During stress the following were also analyzed: stress-induced new regional wall motion abnormalities in 2 contiguous segments; reduced left ventricular contractile reserve (peak/rest based on force, ≤2.0 for exercise and dobutamine, ≤1.1 for vasodilators); and abnormal coronary flow velocity reserve ≤2.0, assessed by pulsed-wave Doppler sampling in left anterior descending coronary artery and abnormal heart rate reserve (peak/rest heart rate) ≤1.80 for exercise and dobutamine (≤1.22 for vasodilators). All patients completed follow-up. RESULTS: According to B-lines at peak stress patients were divided into 4 different groups: group I, absence of stress B-lines (score: 0 to 1; n = 1,389; 64.7%); group II, mild B-lines (score: 2 to 4; n = 428; 20%); group III, moderate B-lines (score: 5 to 9; n = 209; 9.7%) and group IV, severe B-lines (score: ≥10; n = 119; 5.4%). During median follow-up of 15.2 months (interquartile range: 12 to 20 months) there were 38 deaths and 28 nonfatal myocardial infarctions in 64 patients. At multivariable analysis, severe stress B-lines (hazard ratio [HR]: 3.544; 95% confidence interval [CI]: 1.466 to 8.687; p = 0.006), abnormal heart rate reserve (HR: 2.276; 95% CI: 1.215 to 4.262; p = 0.010), abnormal coronary flow velocity reserve (HR: 2.178; 95% CI: 1.059 to 4.479; p = 0.034), and age (HR: 1.031; 95% CI: 1.002 to 1.062; p = 0.037) were independent predictors of death and nonfatal myocardial infarction. CONCLUSIONS: Severe stress B-lines predict death and nonfatal myocardial infarction. (Stress Echo 2020-The International Stress Echo Study [SE2020]; NCT03049995).