Blood Pressure and Aortic Dissection Incidence and Mortality

Quick Takes

  • In a Japanese cohort and a UK cohort, each comprising over 500,000 individuals, hypertension/elevated blood pressure accounted for more than half the population-attributable risk of aortic dissection and dissection-associated death.
  • In a meta-analysis including approximately 1 million individuals, a dose-response effect of elevated blood pressure on aortic dissection risk was observed (relative risk per 20 mm Hg increment of systolic blood pressure, 1.39; per 10 mm Hg increment of diastolic blood pressure, 1.79).

Study Questions:

What is the relationship between blood pressure (BP) and aortic dissection (AD) incidence and mortality?

Methods:

To examine the association between hypertension (HTN)/elevated BP and AD, the investigators analyzed data from two prospective registries, the J-SHC (Japan Specific Health Checkups) study (including independently living Japanese residents aged 40-75 years, from 2008-2015), and the UK Biobank (including volunteer United Kingdom [UK] residents aged 40-69 years). HTN was defined as BP ≥140/90 mm Hg during in-person assessments, or by the use of antihypertensive medication (in J-SHC) or prior diagnosis of HTN (in UK Biobank). Cox proportional hazard analyses were performed to obtain hazard ratios (HRs) for AD and AD-associated death based on systolic BP (SBP), diastolic BP (DBP), and diagnosis of HTN, adjusted for age, sex, and comorbidities including diabetes. The authors also summarized the evidence from these studies, along with previously published prospective studies on BP and AD, in a systematic review and meta-analysis.

Results:

The J-SHC cohort included 534,378 participants (mean age 62.7 years, 43% male), of whom 84 died during a median 4.0 years of follow-up. AD death rate was 4.8 per 100,000 person-years. Male sex, age, and smoking were associated with higher risk of AD death. In multivariable models, elevated BP and HTN were associated with higher risk of AD death (SBP ≥140 vs. <120 mm Hg, hazard ratio [HR] 2.37, 95% confidence interval [CI] 1.21-5.03; DBP ≥90 vs. <80 mm Hg, HR 3.80, 95% CI 2.25-6.45; HTN vs. no HTN, HR 3.57, 95% CI 2.17-6.11). The estimated population-attributable risk percentage (PARp) for AD death was 52% for SBP ≥120 mm Hg, 61% for DBP ≥80 mm Hg, and 58% for HTN.

The UK Biobank cohort included 502,424 participants (mean age 56.5 years, 45.6% male) with no history of AD, of whom 182 developed AD and 63 died of AD during a median 9.0 years of follow-up. Incidence of AD was 4.1 per 100,000 person-years. Male sex, age, smoking, and connective tissue disorders were associated with higher risk of AD. In multivariable models, elevated BP and HTN were associated with higher risk of AD (SBP ≥180 vs. <120 mm Hg, HR 4.69, 95% CI 1.88-11.68; DBP ≥110 vs. <80 mm Hg, HR 11.82, 95% CI 6.43-21.72; HTN vs. no HTN, HR 2.68, 95% CI 1.78-4.04). The estimated PARp for AD incidence was 62% for SBP ≥120 mm Hg, 36% for DBP ≥80 mm Hg, and 53% for HTN.

The systematic review and meta-analysis included six publications in addition to the J-SHC and UK Biobank data (three Scandinavian, one British, one Taiwanese, one Hawaiian). The summary relative risk (RR) of AD for HTN, based on data from ~4.6 million individuals, was 3.07 (95% CI, 2.15-4.38). Based on data from ~1 million individuals, per 20 mm Hg increment of SBP, summary RR was 1.39 (95% CI, 1.16-1.66) and per 10 mm Hg increment of DBP was 1.79 (95% CI, 1.51-2.21). The 95% CIs for RR were >1.0 at SBP >132 mm Hg and DBP >75 mm Hg.

Conclusions:

HTN and elevated BP are strongly associated with AD, in a dose-dependent fashion. Even modest elevations in BP are associated with increased risk of AD.

Perspective:

Aside from smoking, HTN is the most important modifiable risk factor for AD and AD death. The analyses presented in this paper are large and include individuals from various ethnic backgrounds. It is important to note that selection bias toward healthy individuals was likely in the J-SHC and UK Biobank cohorts, and AD risk is probably higher in some populations. In the US in particular, a majority of patients with HTN do not have adequate control. Proactive medication titration, patient engagement with home BP readings, and close long-term follow-up are important strategies for ensuring appropriate BP management.

Clinical Topics: Cardiac Surgery, Diabetes and Cardiometabolic Disease, Invasive Cardiovascular Angiography and Intervention, Prevention, Vascular Medicine, Cardiac Surgery and Arrhythmias, Interventions and Vascular Medicine, Hypertension, Smoking

Keywords: Aneurysm, Dissecting, Antihypertensive Agents, Blood Pressure, Cardiac Surgical Procedures, Connective Tissue Diseases, Diabetes Mellitus, Ethnic Groups, Hypertension, Metabolic Syndrome, Primary Prevention, Risk Factors, Smoking, Vascular Diseases


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