Prognostic significance of baseline and serial changes in electrocardiographic strain pattern in resistant hypertension.

OBJECTIVES

The prognostic importance of serial changes in electrocardiographic strain pattern of lateral ST-depression and T-wave inversion is unclear. The objective was to evaluate the significance of baseline and serial changes in strain pattern as predictors of cardiovascular morbidity and mortality in patients with resistant hypertension.

METHODS

At baseline and during follow-up, 532 resistant hypertensive patients had the presence of strain pattern examined on 12-lead ECGs. Other clinical laboratory, echocardiographic and ambulatory blood pressure data were obtained. Primary endpoints were a composite of total cardiovascular events and mortality. Strokes and coronary heart disease events were secondary endpoints. Multiple Cox regression assessed the associations between strain pattern and subsequent endpoints.

RESULTS

At baseline, 115 patients (21.6%) presented the strain pattern and during follow-up, 17 patients regressed and 22 developed new strain pattern. After a median follow-up of 4.8 years, 69 patients died, 46 from cardiovascular causes; and 107 cardiovascular events occurred, 44 strokes and 42 coronary heart disease events. After adjustment for several cardiovascular risk factors, including time-varying ambulatory blood pressures and electrocardiographic voltage criteria of left ventricular hypertrophy, the persistence or development of strain during follow-up was a predictor of the composite endpoint (hazard ratio 1.97, 95% confidence interval 1.19-3.25), all-cause mortality (hazard ratio 1.99, 95% confidence interval 1.10-3.61) and of stroke (hazard ratio 3.09, 95% confidence interval 1.40-6.81). The combination of strain pattern and left ventricular hypertrophy voltage criteria improved stratification of cardiovascular risk.

CONCLUSION

Serial changes in electrocardiographic strain pattern during follow-up predict cardiovascular morbidity and mortality in resistant hypertensive patients. Regression or prevention of the strain pattern during antihypertensive treatment may be a therapeutic goal to improve prognosis.