The effect of a change in antihypertensive treatment on orthostatic hypotension in older adults: A systematic review and meta-analysis

Background: Orthostatic hypotension (OH) is common in older adults with hypertension. Antihypertensive treatment (AHT) prevents cardio- and cerebrovascular events. However, physicians are concerned to cause OH, making them hesitant to initiate or augment AHT in older adults with hypertension. Methods: We systematically researched electronic databases for trials with older participants (>= 65 years) with hypertension and OH assessment after initiating, discontinuing, or augmenting AHT. Study quality was assessed using the ROBINS-I tool. Meta-analyses on OH prevalence and postural blood pressure (BP) drop were performed. Results: Twenty-five studies (26,695 participants) met inclusion criteria, of which fifteen could be included in the meta-analyses. OH prevalence decreased after AHT initiation or augmentation (risk ratio 0.39 (95 % CI = 0.21-0.72; I-2 = 47 %; p < 0.01), n = 6 studies), but also after AHT discontinuation (risk ratio 0.39 (95 % CI = 0.28-0.55; I-2 = 0 %; p < 0.01), n = 2 studies). Postural BP drop did not change after initiation or augmentation of AHT (mean difference 1.07 (95 % CI = -0.49-2.64; I-2 = 92 %; p = 0.18), n = 11 studies). The main reason for ten studies not to be included in the meta-analyses was absence of baseline OH data. Most of these studies reported OH incidences between 0 and 2 %. Studies were heterogeneous in OH assessment methods (postural change, timing of BP measurements, and OH definition). Risk of bias was moderate to serious in twenty studies. Conclusion: Results suggest that AHT initiation or augmentation decreases OH prevalence, implying that the risk of inducing OH may be overestimated in current AHT decision-making in older adults. However, the overall low level of evidence and the finding that AHT discontinuation reduces OH prevalence limit firm conclusions at present and highlight an important research gap. Future AHT trials in older adults should measure OH in a standardized protocol, adhering to consensus guidelines to overcome these limitations.