Coronary vascular function in patients with resistant hypertension and normal myocardial perfusion: a propensity score analysis

AIMS: Impaired myocardial perfusion reserve (MPR) may occur earlier than coronary atherosclerosis and it may be an early manifestation of developing coronary artery disease (CAD) in patients with resistant hypertension (RH). We evaluated the relationship between RH and MPR in patients with systemic arterial hypertension after balancing for coronary risk factors. METHODS AND RESULTS: We studied 360 subjects without overt CAD and normal myocardial perfusion at stress-rest 82Rb positron emission tomography/computed tomography. To account for differences in baseline characteristics between patients with resistant and controlled hypertension, we created a propensity score-matched cohort considering clinical variables and coronary risk factors. Before matching, patients with RH were significantly older, had higher prevalence of male gender and hypercholesterolaemia, and showed significantly lower global hyperaemic myocardial blood flow (MBF) and MPR compared with those with controlled hypertension, while baseline MBF and coronary artery calcium (CAC) content were similar in both groups. After matching, there were no significant differences in clinical variables and coronary risk factors between patients with resistant and controlled hypertension, but patients with RH still had lower hyperaemic MBF and MPR (both P < 0.001). At univariable and multivariable linear regression analyses, age, RH, and CAC resulted significant predictors of lower MPR values (all P < 0.05). CONCLUSION: After balancing clinical characteristic by propensity score analysis, patients with RH had a blunted hyperaemic MBF and MPR compared with patients with controlled hypertension. The identification of impaired MPR could help to identify early structural alterations of the arterial walls in patients with RH.