Abstract 13346: Systolic Pressure-Global Strain Index Predicts Outcome Better than Global Strain
Background: Global longitudinal systolic strain (GSS) is afterload dependent. Preserved GSS in the setting of increased afterload may be a marker of superior ventricular systolic function and better outcome.
Objective: Determine the utility of afterload adjusted GSS for prediction of outcome in patients with a wide range of systolic blood pressure.
Methods: One-hundred forty-three patients (80 with, and 63 without hypertension), no known coronary disease, and ejection fraction (EF) ≥50% were enrolled. Systolic blood pressure-strain index (SPSI) was derived for each patient using SBP recorded at the time of echocardiography (SPSI = GSS x SBP (mm Hg)/100 mm Hg). Patients were followed for cardiac events (cardiac death, nonfatal infarction and heart failure).
Results: The mean age was 53 ± 14 years. SBP ranged from 81 to 193 mm Hg, GSS from -8.4 to -30.7%, and SPSI from -9.6 to -40%, with more negative values of GSS and SPSI representing greater contractility. There were 22 events (15%) over a mean follow up of 1.9 ± 1.1 years. SPSI (p =0.002, HR 0.88, 95%CI 0.82-0.95) and Left ventricular hypertrophy (LVH) (p= 0.006, HR 3.26, 95% CI 1.4-7.6) were univariate predictors of cardiac events by Cox regression. Ejection fraction (p=0.321) and GSS (p=0.079) were not significant predictors. Multivariate analysis showed that SPSI (p = 0.011, HR 0.91, 95% CI 0.84-0.98), and LVH (p = 0.045, HR 2.5, 95% CI 1.0-6.0), were independent predictors of cardiac events. ROC analysis showed a C statistic for GSS of 0.62 (p =0.084, 95% CI 0.47-0.76) and for SPSI of 0.70 (p=0.003, 95% CI 0.57-0.83). The optimal cutoff for SPSI was -23 %. Kaplan-Meier analysis showed mean survival to be significantly higher in patients with SPSI > -23 % vs SPSI < - 23 % (5.9 years vs 3.0 years respectively, P=0.001).
Conclusion: Systolic pressure-strain index is an independent predictor of cardiac events in patients with normal EF and a wide range of systolic pressure. The prognostic value of SPSI is greater than GSS in these subjects.
- © 2013 by American Heart Association, Inc.