Prognostic relevance of electrocardiographic Tpeak-Tend interval in the general and in the hypertensive population: data from the Pressioni Arteriose Monitorate E Loro Associazioni study.

Abstract

EKG Tpeak-Tend (Tp-Te) interval, an index of transmural dispersion of myocardial repolarization, is gaining interest as possible cardiovascular prognostic variable. Evidence that this is the case in the general population is scanty, however. This was tested in the Pressioni Arteriose Monitorate E Loro Associazioni population. EKG, echocardiographic, office, home and ambulatory (24-h) blood pressure (BP), metabolic and laboratory data were assessed. Cardiovascular and all-cause mortality were evaluated over a mean follow-up of 16 years. Repetition of all measurements after 10 years allowed to evaluate also the risk of developing office and out-of-office hypertension and echocardiographic left ventricular hypertrophy. At baseline, Tp-Te adjusted for confounders (c) showed a significant correlation with office, home and 24-h blood pressure but not with left ventricular mass. The cTp-Te value predicted the risk of cardiovascular and all-cause mortality before and after adjustment for demographic and clinical variables, the increase being 31 and 13% for 1-SD cTp-Te increase, respectively (P < 0.0001 and P < 0.002). This was the case also in hypertensive patients in which the corresponding increase in risk with 1-SD increase of Tp-Te was 47 and 25% (P < 0.05). cTp-Te did not predict the 10-year risk of developing office, home, ambulatory hypertension and left ventricular hypertrophy. Tp-Te interval retains an independent prognostic value both in the general population and in its hypertensive fraction. This easily and cheaply obtainable variable may be employed for improving cardiovascular-risk stratification, representing a useful measure to add to the recommended screening in hypertension.