Significance of an Increase in Diastolic Blood Pressure During a Stress Test in Terms of Comorbidities and Long-Term Total and CV Mortality.

BACKGROUND: A decrease in diastolic blood pressure (DBP) with exercise is considered normal, but the significance of an increase in DBP has not been validated. Our aim was to determine the relationship of DBP increasing on a stress test regarding comorbidities and mortality.
METHODS: Our database was reviewed from 1993 to 2010 using the first stress test of a patient. Non-Minnesota residence, baseline cardiovascular (CV) disease, rest DBP <60 or >100 mm Hg, and age <30 or ≥80 were exclusion criteria. DBP response was classified: normal if peak DBP-rest DBP < 0, borderline 0-9, and abnormal ≥10 mm Hg. Mortality was determined from Mayo Clinic records and Minnesota Death Index. Logistic regression was used to determine the relationship of DBP response to the presence of comorbidities. Cox regression was used to determine total and CV mortality risk by DBP response. All analyses were adjusted for age, sex, and resting DBP.
RESULTS: Twenty thousand seven hundred sixty patients were included (51 ± 11 years, female n = 7,314). Rest/peak averaged DBP 82 ± 8/69 ± 15 mm Hg in normal vs. 79 ± 9/82 ± 9 mm Hg in borderline vs. 76 ± 9/92 ± 11 mm Hg in abnormal DBP response. There were 1,582 deaths (8%) with 557 (3%) CV deaths over 12 ± 5 years of follow-up. In patients with borderline and abnormal DBP response, odds ratios for obesity, hypertension, diabetes, and current smoking were significant, while hazard ratios for total and CV death were not significant compared with patients with normal DBP response.
CONCLUSIONS: DBP response to exercise is significantly associated with important comorbidities at the time of the stress test but does not add to the prognostic yield of stress test.