Effects of intensive blood-pressure treatment on myocardial work in elderly hypertensive patients: A subcenter study of the STEP randomized controlled trial

Abstract

Background: The benefits and safety of intensive blood pressure treatment in elderly hypertensive patients have been proved in the STEP trial. However, relevant mechanisms for intensive treatment are lacking.

Hypothesis: We aimed to explore whether intensive blood pressure treatment is associated with left ventricular systolic function changes as evaluated by myocardial work (MW) parameters in elderly hypertensive patients compared to the standard.

Methods: Patients were randomized to the intensive group (n = 66, median age 66 years, 42.4% male) with a systolic blood pressure (SBP) goal of 110 to <130 mmHg or the standard treatment group (n = 50, median age 63.5 years, 30% male) with an SBP goal of 130-<150 mmHg in this subcenter study of the STEP trial. There was no pre-randomization echocardiographic collected. Echocardiographic exam was produced at 1-year (phase 1) and 3-year (phase 2) post-randomization.

Results: In phase 1, SBP was already significantly lower in the intensive treatment group than in the standard treatment group (126.5 vs. 132.1 mmHg, p < .05). During a median follow-up of 40 months, in phase 2, the intensive group still had a lower SBP than the standard treatment group (125.0 vs. 135.3 mmHg, p < .05). Both global work index (GWI) and global constructive work (GCW) decreased significantly in phase in the intensive treatment group but not in the standard group (p < .05). Global wasted work (GWW) increased and global work efficiency (GWE) declined in both groups from phase 1 to phase 2 while no significant difference between the treatment effects. Similarly, left ventricular ejection function (LVEF) and global longitudinal strain (GLS) decreased in the two groups. The multivariate linear regression analysis showed the intensive treatment appeared to be an independent predictor of the ΔGWI (β = -110.92; 95% CI, -197.78 to -30.07, p = .008) and ΔGCW (β = -135.11; 95% CI, -220.33 to -49.88, p = .002).

Conclusions: In elderly hypertensive patients, lower SBP was associated with decreased GWI and GCW and intensive BP treatment did not improve global MW efficiency.

Keywords: elderly hypertension; intensive blood pressure treatment; left ventricular; myocardial work.