Large Study Suggests That Death Comprises Higher Proportion of Major CV Events in Patients with Greater CV Risk

Summary

A review of 51 clinical trials of antihypertensive agents suggested a method of creating simple equations to determine a patient's risk of suffering death, major cardiovascular (CV) death, or other CV disease once the patient's risk of CV mortality is known. The technique incorporated the latest ESH-ESC Hypertension Guidelines [J Hypertens 2013].

  • Hypertensive Disease
  • Cardiology Clinical Trials
  • Hypertensive Disease
  • Cardiology Clinical Trials
  • Cardiology

A review of 51 clinical trials of antihypertensive agents suggested a method of creating simple equations to determine a patient's risk of suffering death, major cardiovascular (CV) death, or other CV disease once the patient's risk of CV mortality is known, according to Antonella Zambon, PhD, University of Milano-Bicocca, Milan, Italy. The technique incorporated the latest European Society of Hypertension/European Society of Cardiology (ESH/ESC) Hypertension Guidelines [Mancia G et al. J Hypertens 2013].

Beginning in 1999, guidelines began stratifying the risk that hypertensive patients will suffer death [WHOISH Guidelines Subcommittee. J Hypertens 1999], but the guidelines have become more expansive, with European guidelines introduced in 2003 [ESH/ESC Guidelines Committee. J Hypertens] and 2007 [Mancia G et al. J Hypertens], and the expansive definitions used in the Framingham classification growing to include more adverse events such as organ damage, angina, or coronary insufficiency within the category of major CV events. Accordingly, definitions of major CV events have come to be somewhat mutable, and vary between clinical trials, according to Prof. Zambon. This makes it sometimes difficult to estimate a patient's risk of death based merely on their risk of having a major CV event, he added.

For the risk of CV death within 10 years, the 2013 ESH/ESC Hypertension Guidelines retain the risk stratifications of low (<1% risk), moderate (1% to 5%), high (5% to 10%), and very high (>10%) risk, Prof. Zambon noted. The new guidelines add nonfatal stroke and nonfatal myocardial infarction to the list of what constitutes a major CV event, he said.

The researchers identified 61 clinical trials, of which 51 were retained for analyses. Trials were included if the study population was comprised of ≥40% hypertensive patients and ≥2500 patient-years of observations. This resulted in a database that included 15,164 CV deaths and 1,674,427 patient-years of follow-up.

The researchers found that the ratio of the CV event rates to the CV death rate varied with disease severity, with CV death representing a larger fraction of major CV events when the risk of CV mortality was higher (Table 1). When the rate of CV death was 2.5 per 1000 patient-years, the rate of major CV events was 3.86, but when the rate of CV death rose to 7.5 per 1000 patient-years, the rate of major CV events decreased to 2.69. Furthermore, when the CV death rate was 12.5 per 1000 patient-years, the rate of major CV events declined to 2.28.

Table 1.

Ratios of Various Types of Events to CV Mortality According to Level of CV Risk

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