Hypotensive Drugs and Orthostatic Hypotension–Related Syncopal Falls in Older Adults With Dementia

This study compared 522 Italian women ≥65 years of age (average, 83 years) with a diagnosis of dementia who had a syncopal episode (n = 324; 67.8%) with those who had an unexplained fall (n = 168; 32.2%) in the previous 3 months. Syncopal falls were related to orthostatic hypotension in 170 participants (48.0%) and occurred more frequently in patients receiving nitrates, alpha blockers, and combinations of diuretics with either ACE inhibitors or alpha blockers. Multivariate analysis confirmed greater risk with nitrates (RR, 1.77), combinations of ACE inhibitors and diuretics (RR, 1.66), and combinations of ACE inhibitors and nitrates (RR, 2.32).

Patients with worse dementia had significantly more falls and patients with better cognition had more syncopal episodes. Patients with a pacemaker had syncopal falls but no other falls. ACE inhibitors alone were not associated with a difference in risk between the groups, but the combinations with diuretics or nitrates were significantly associated, as were combinations of alpha blockers and diuretics. There was no comparison with non-fallers.

The definition of syncope was a decrease of 20 mm Hg or more in systolic blood pressure and 10 mm Hg or more in diastolic blood pressure measured at 1 and 3 minutes of standing, within 72 hours of the last episode of fall or syncope. This definition may have missed many patients with orthostasis, as the recent TILDA study measured blood pressure continually and showed that the blood pressure nadir occurs at 15 seconds after standing. TILDA showed a correlation with orthostatic hypotension and falls in 4127 cognitively intact Irish adults ≥50 years of age. A recent analysis of the SPRINT trial, where orthostatic blood pressure was also measured after the 1-minute interval in cognitively intact patients, showed no correlation with falls in the more tightly controlled group.  

In this study, ACE inhibitors, ARBs, and calcium channel blockers were not associated with an increased risk of syncope, and the MOBILIZE study showed a lower risk of falls associated with these three classes of blood pressure meds.¹ Medications that have been shown to cause orthostatic hypotension—alpha blockers, nitrates, and diuretics and their combinations—were associated with syncope. We need to treat our older adults’ hypertension aggressively to prevent strokes and mortality, but it seems that the choice of blood pressure meds matters. Evidence is mounting that we should use ACE inhibitors, ARBs, and calcium channel blockers, and, if possible, avoid alpha blockers, nitrates, and diuretics.

The authors of this study, as in the TILDA and SPRINT trials, did not mention the rates of dehydration, as that may be significantly contributing to falls and syncope. And diuretics may be contributing to dehydration. We can make sure our patients have adequate fluid intake of ≥2 liters. As explained previously, older adults need more fluid intake, and most do not adequately sense thirst. Limiting diuretic use to CHF exacerbation only and looking for causes of edema in the absence of pulmonary edema, such as obstructive sleep apnea, allows us to decrease use of diuretics.

Reference

1. Lipsitz LA, Habtemariam D, Gagnon M, et al. Reexamining the effect of antihypertensive medications on falls in old age. Hypertension. 2015;66(1):183-189. http://hyper.ahajournals.org/content/66/1/183.long