Very short-term blood pressure variability by pulse transit time-based measurements during night-time predicts future cardiovascular events in patients with ischemic heart disease.

Blood pressure (BP) variability (BPV) is associated with an increased risk of cardiovascular events, independent of absolute BP values. However, the predictive significance of very short-term BPV, occurring within seconds or minutes, in patients with ischemic heart disease (IHD) has yet to be established. This prospective study involved 206 consecutive hospitalized patients with IHD (mean age 67.6 years, 78.2% male) who underwent pulse transit time (PTT)-based continuous BP recording during the night-time. Very short-term BPV was assessed by standard deviation (SD), coefficient of variation (CV), and variation independent of mean (VIM) of PTT-BP. Clinical outcome data were collected. When the patients were categorized into two groups according to the median value of very short-term BPV, Kaplan-Meier analysis revealed that patients with elevated SD, CV, and VIM of systolic and diastolic PTT-BP were associated with lower event-free survival rates from the composite cardiovascular events including cardiac deaths, worsening heart failure cases, nonfatal myocardial infarctions, unplanned revascularizations, and strokes over a median follow-up of 797 days. In a multivariate Cox proportional hazards analysis adjusting for confounding variables, each parameter as a continuous variable was independently associated with adverse events. Incorporating very short-term BPV into basic models had a significant impact on risk reclassification and integrated discrimination for cardiovascular outcomes. In conclusion, the identification of patients with elevated very short-term BPV during the night-time through a PTT-driven approach helps stratify the future risk in IHD patients.