Saturday, December 29, 2007

Exercise-induced blood pressure increases predict survival

Exercise-induced blood pressure increases predict survival

24 December 2007

MedWire News: An increase in systolic blood pressure (SBP) during exercise stress testing appears to be associated with improved survival in men, researchers report.

Data suggest that exercise-induced increases in SBP are prognostic for cardiovascular (CV) mortality, independent of age, resting blood pressure, and common cardiac risk factors.

To determine whether SPB measured during exercise stress testing adds prognostic information to CV mortality, Manish Gupta, from Lenox Hill Hospital in New York City, USA, and colleagues evaluated SBP responses in 6213 consecutive men referred for exercise stress testing for clinical reasons.

Patients were grouped according to whether their median change in exercise induced SPB was ≤43 mmHg or ≥44 mmHg, representing low and normal increases in SPB, respectively.

The results demonstrated that patients with increases in baseline SBP ≥44 mmHg had significantly lower mortality than patients with increases in baseline SBP ≤43 mmHg, at 8.2% versus 13.7%, respectively. This difference in improved survival remained after controlling for age, exercise capacity, ST abnormalities, history of myocardial infarction or congestive heart failure, hypertension, and use of a beta blocker.

The researchers also found that the survival benefit was incremental, with patients in the highest quartile of increased SBP (≥76 mmHg) having significantly lower CV mortality than patients in the lowest quartile (≤42 mmHg), at 7.3% versus 16.7%, respectively. Importantly, a history of hypertension was independently and significantly associated with a higher SPB response to exercise.

The team concludes in the American Journal of Cardiology that an increase in SPB with exercise stress test predicts cardiovascular mortality independent of age, exercise capacity, and ST-segment abnormalities.

They add that "an increase in systolic BP≥ 44 mmHg from baseline [is] associated with survival even in patients with a history of hypertension," and emphasize that the findings are applicable only to men because exercise testing results have been shown to differ between genders.

Source: Am J Cardiol 2007; 100: 1609-1613

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