For patients with type 2 diabetes, apparent treatment-resistant hypertension increases risk for cardiovascular events and mortality, according to study results published in Diabetes Care.
The prospective study included patients with type 2 diabetes who were diagnosed with apparent treatment-resistant hypertension according to mean office blood pressure (BP) levels during the first year of follow-up (N=646). Patients then underwent 24-hour ambulatory BP monitoring and were reclassified as white-coat/controlled or true/uncontrolled hypertension according to traditional BP cutoffs and 2017 American College of Cardiology/American Heart Association criteria. The researchers used multivariate Cox analyses to determine associations between treatment-resistant hypertension diagnoses and the occurrence of microvascular and macrovascular complications, as well as all-cause and cardiovascular mortality.
Using traditional hypertension criteria, apparent treatment-resistant hypertension was present in 44.6% of patients, while the newer 2017 criteria identified 50% of patients as having apparent treatment-resistant hypertension.
During a median follow-up of 10 years, 177 patients had a cardiovascular event, 200 had a renal event (new microalbuminuria or deteriorated renal function), 156 had new or worsening retinopathy, 174 had new or worsening peripheral neuropathy, and 222 died. Of the cardiovascular events, 145 were major, and of the patients who died, 101 died from cardiovascular disease.
Compared with patients who did not have treatment-resistant hypertension, those with the condition had increased risk for all cardiovascular and mortality outcomes with hazard ratios (HRs) ranging from 1.64 to 2.16 in multivariate-adjusted models. However, apparent treatment-resistant hypertension did not predict any microvascular outcomes.
Patients with true treatment-resistant hypertension had an increase in HR (range, 1.81-2.25) for cardiovascular mortality, all-cause mortality, and cardiovascular event outcomes. True treatment-resistant hypertension also predicted renal outcomes (HR, 1.37-1.38).
Patients with white-coat/controlled resistant hypertension also had increased risk (HR, 1.33-1.86) for cardiovascular and mortality outcomes, which fell between the risks found for those with nonresistant hypertension and true treatment-resistant hypertension.
The study had several limitations. Of note, diagnosis of white-coat/true treatment-resistant hypertension was based on a single ambulatory BP reading, and there was a small time lag between patients’ clinical and ambulatory BP measurements.
“Interventional studies of intensive risk factor management in these high-risk patients are warranted to verify whether such increased cardiovascular and renal risks could be reduced,” the researchers wrote.
Cardoso CRL, Leite NC, Bacan G, Ataide DS, Gorgonio LKC, Salles GF. Prognostic importance of resistant hypertension in patients with type 2 diabetes: the Rio de Janeiro type 2 diabetes cohort study [published online October 16, 2019]. Diabetes Care. doi:10.2337/dc19-1534