[The correlation between postural hypotension and myocardial infarction in the elderly population]

To investigate the association between the systolic/diastolic orthostatic hypotension (OH-S/OH-D) and myocardial infarction (MI) in the elderly.

Health screening physical examination were carried in 1081 subjects without MI aged over 65 years in Guangzhou Military region. The orthostatic blood pressure and heart rate were measured in supine position after resting for more than 5 minutes and at 0 and 2 minutes after standing. All the cases were divided into systolic or diastolic group on the basis of definition of orthostatic hypotension and followed up by telephone or inpatient medical records with mean period of 315.8 days. The primary endpoint was MI occurrence.

The prevalence of OH in this cohort was 24.5% (OH-S/OH-D: 19.3%/17.2%). Significant differences in the occurrence of OH and OH-S were found in the elderly and the very elderly subjects (≥ 80 years) (26.1% vs 20.1%, P = 0.045 ; 21.0% vs 14.6%, P = 0.018), while no difference was found in OH-D. The prevalence of MI in the OH positive subjects was significantly higher than that in the OH negative subjects, as well as in OH-S or OH-D group. After adjustment of age, supine blood pressure, creatinine and cerebrovascular history by logistic regression, the association was observed between MI and OH (HR 15.635, 95%CI 3.299 - 74.091, P = 0.001), OH-S(HR 8.760, 95%CI 2.487-30.851, P = 0.001)and OH-D(HR 3.889, 95%CI 1.097 - 13.790, P = 0.035).

OH-S and OH-D hypotension are robust predictors for MI in the elderly.