Prevalence, predictors, and outcomes of both true- and pseudo-resistant hypertension in the action to control cardiovascular risk in diabetes trial: a cohort study

Resistant hypertension (RH) has been poorly studied due to the difficulty in distinguishing it from nonadherence-the exclusion of which is necessary to accurately diagnose RH. Therefore, little is known about the prevalence, predictors, and outcomes of true RH. We evaluated 1838 patients from the standard blood pressure (BP) arm of the Action to Control Cardiovascular Risk in Diabetes Trial. We classified patients into three groups: "true RH", "pseudo-RH" (i.e., patients with BP levels that would classify them as RH but who were non-adherent), and "other" (i.e., those who could not be classified as having "true RH" or "pseudo-RH"). We examined predictors of true and pseudo-RH and the relationship between true RH and the composite outcome of nonfatal MI, nonfatal stroke, or cardiovascular death. Among 1838 participants with complete information, 489 (26.6%) met the definition of true RH, and 94 (16.1%) RH patients had "pseudo-RH" on ≥1 visit over the first 12 months. Predictors of RH included: baseline SBP ≥ 160 mmHg (OR = 8.79; 95% CI: 5.70-13.68) and baseline SBP between 140-159 (OR = 2.91; 95% CI: 2.13-4.00) compared to SBP < 140, additional baseline BP medication (OR = 3.40; 95% CI: 2.83-4.11), macroalbuminuria (OR = 2.35; 95% CI: 1.50-3.67), CKD (OR = 1.53; 95% CI: 0.99-2.33), history of stroke (OR = 1.73; 95% CI: 1.04-2.82), and black race (OR = 1.39; 95% CI: 1.02-1.88); the cross-validated C-statistic was 0.80. "True RH" patients had a 65% increased hazard in composite outcome (HR = 1.65; 95% CI: 1.13-2.42). In conclusion, the majority of patients classified as having RH had "true RH," which was more common among those who are black, have macroalbuminuria, CKD, stroke, higher baseline SBP, and are taking more baseline antihypertensives. These patients are at increased risk for cardiovascular and mortality events.