Abstract MP72: The Effects of Antihypertensive Class on Falls, Syncope, and Orthostatic Hypotension in Older Adults: the ALLHAT Trial

Background: Hypertension treatment is believed to contribute to falls, syncope, and orthostatic hypotension (OH), common events among older adults. Whether choice of antihypertensive agent influences the incidence of these adverse outcomes is unknown. Hypothesis: Chlorthalidone and atenolol are associated with higher risk of fall, syncope, and OH, compared with amlodipine or lisinopril. Methods: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) was a randomized clinical trial that compared the effects of first-step therapy with amlodipine, lisinopril, or chlorthalidone on fatal coronary heart disease or nonfatal myocardial infarction (1994-2002). We linked participants to CMS and VA claims to determine the incidence of fall, syncope, OH, or a composite outcome (any of fall, syncope, or OH), using Cox regression. The association of baseline or 1-month add-on atenolol use with outcomes was determined via Cox models adjusted for age, sex, race, and randomized drug assignment. Results: Among 23,964 participants (mean age 70.4 ± 6.7 years, 43% women, 31% black), 927 participants took atenolol at baseline. Over a mean follow-up of 4.9 years, there were 267 fall, 755 syncope, 249 OH, and 1,157 composite claims with no significant differences in the cumulative incidence of events across randomized drug assignments ( Figure ). Compared with chlorthalidone, amlodipine and lisinopril were not associated with falls (HR [95%CI]: 1.36 [0.90-2.05] and 0.80 [0.47-1.36], respectively), syncope (0.96 [0.77-1.21] and 1.07 [0.85-1.34], respectively), OH (0.98 [0.66-1.45] and 1.24 [0.87-1.76], respectively), or the composite outcome (1.01 [0.84-1.21] and 1.07 [0.92-1.22], respectively). Similarly, atenolol use was not associated with any of the 3 individual or composite claims. Conclusions: Choice of antihypertensive agent has no effect on risk of fall, syncope, or OH in older adults. This observation should simplify the choice of initiating antihypertensive therapy in this population.