The physiologic and prognostic value of regional longitudinal strain during dipyridamole stress echocardiography

Abstract

Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Investigaciones Médicas, Cardiodiagnostic Background. Regional apical longitudinal strain (RALS) allows to corroborate the diagnosis of regional wall motion abnormalities (RWMA) during dipyridamole stress echocardiography (DSE) on a quantitative basis but data on the prognostic value are missing. Objectives. The to evaluate the physiologic correlates and prognostic value of RALS vs. RWMA during DSE. Methods. In a single center, observational design we initially evaluated 150 patients (pts), mean age 68.3 ± 9.6 years, 50.7% men referred for DSE. RALS was defined as the average of the four apical segments from the 3 apical views. Any increase in the percentage of deformation was considered normal. Coronary flow velocity reserve (CFVR) was also assessed in mid-distal left anterior descending (LAD) coronary artery by pulsed-wave Doppler. Pts were divided into two groups (G). G1: patients with normal RALS, and G2: patients with abnormal RALS. Major cardiovascular event was considered to be: cardiovascular death, acute myocardial infraction (AMI), stroke or needs for revascularization after 3 months All patients were followed-up. Results. RALS success rate was 94.6% (142 pts), since 8 pts were excluded for inadequeate window. Eighty-seven patients (61.3%) were included in G1 and 55 (38.7%) pts in G2. The mean follow-up was 36 ± 0.93 months. There were no differences in the resting RALS between the G1 and G2 (-22.3% ± 3.3 vs -21.25% ± 4.9, p = NS), but significant differences in the peak dipyridamole effect (-26.3% ± 4.2 vs -18.8% ± 4.1, p < 0.001). Pts G1 showed less RWMA than pts G2 (G1 3.4% vs G2 90 %), p < 0.001) and higher CFVR (G1= 2.6 ± 0.5 vs G2 = 1.6 ± 0.4, p < 0.001). Adequeate CFVR showed high concordance with the increase in RALS evaluated by Kappa Index 0.95, p 0.001 (Pts G1= 98.9% vs pts G2= 96.4%). In the long-term follow up, 24 pts experienced events: 3 deaths, 3 non-fatal myocardial infarctions, 2 stroke and 16 late revascularizations. Pts with normal RALS had a better event-free survival (G1= 90.8% vs G2 = 70.9%, log Rank p < 0.007, HR: 2.92; 95% CI: 1.27-6.68, p 0.011) (figure 1). In the multivariate analysis of logistic regression, adjusted for age, the RALS was an independent predictor of event. In G2 no significant differences were detected in event free survival in pts with and without visual dyssynergies during DSE (73.7 vs 67.7, respectively (p = ns) Conclusions. A mismatch between RALS and visually assessed RWMA occurs in a significant proportion of patients, and RALS is better correlated to physiologic (CFVR) and prognostic standards. Abnormal RALS during DSE predicted worse outcome, regardless of the RWMA. Quantitative stress echocardiography is possible feasible and useful during DSE. Abstract Figure. RALS in DSE and Event Free Survival