Orthostatic hypotension and cardiovascular events—Closing the link?

Orthostatic hypotension (OH), classically defined as a sustained drop of more than 20 mm Hg for systolic blood pressure (SBP) and/or more than 10 mm Hg for diastolic blood pressure (DBP) three minutes after standing upright or during a head-up tilt,1, 2 has been associated with an increased risk of cardiovascular disease. In fact, previous studies have reported a significant association of OH with cardiovascular morbidity and mortality,3, 4 atrial fibrillation,5 cognitive decline,6 among other clinical conditions. Being strongly associated with aging7 and with the current demographic trends showing an increase in the proportion of the population above 65 years of age, the burden of OH is also expected to increase and contribute to a greater risk of falling, disability and reduced quality of life in the elderly.8, 9 Therefore, as a serious public health problem, OH must be comprehensively addressed and efficient management options are needed to reduce its associated hazards. Notwithstanding the association of OH with several clinical conditions and significant events, the definition of OH as an independent cardiovascular risk factor remains a controversial topic, motivating the systematic review and meta-analysis published by Min et al.10 After a thorough literature search, the authors included 15 prospective cohort studies that met the inclusion criteria. Most of these studies included European populations (eight studies), and the remaining were performed either in North America (five studies) or Asia (three studies), representing general population (13 studies), one study with a hypertensive cohort and another one with a mixed cohort with both hypertensive and diabetic participants. The follow-up ranged from 1.0 to 26.0 years, and the participants’ age varied from 45 to 84 years. The results consistently demonstrated that patients with OH are at higher risk of several cardiovascular diseases, particularly atrial fibrillation (AF), with a pooled HR of 1.51 (CI: 1.28-1.79), and heart failure (HF), with a pooled HR of 1.34 (CI: 1.17-1.52). Additionally, OH was also shown to increase the risk of developing coronary heart disease and myocardial infarction, with pooled HR of 1.44 (CI: 1.18-1.75) and 1.52 (CI: 1.12-2.06), respectively. This updated review consistently confirmed that OH significantly increases the risk of several cardiovascular diseases, with postural changes in SBP and/or DBP being associated with a higher risk of AF, HF and ischemic heart disease, in a meta-analysis that included a large number of studies with quite large samples and a wide mean follow-up length. The subgroup analysis provided further and novel arguments indicating the possibility of regional-specific variations in the strength of association. Overall, these findings support the hypothesis that OH is an important manifestation of undetected cardiovascular disease that must be taken into good consideration, particularly in the management of elderly patients in which OH is expected to be more prevalent and concomitant morbidities and complex therapeutic regimens are commonly in place. Also, the close link of OH with aging and its association with the risk of fall in the elderly should not be overlooked since falls constitute a major cause of morbidity and mortality in this particular subgroup11 and preventive strategies to tackle this serious public health problem are of the utmost importance. Future studies should address whether targeted therapies are able to reduce the hazards of OH in the overall population, with a particular emphasis in the elderly. The author reports no conflict of interest.