Cardiovascular Risk of Essential Hypertension: Influence of Class, Number, and Treatment-Time Regimen of Hypertension Medications

A number of observational studies have found that treated hypertensive patients, even those with controlled clinic blood pressure (BP), might have poorer prognosis than untreated hypertensives. Different trials have also shown that relatively low cardiovascular disease (CVD) risk cannot be achieved in high-risk hypertensive patients, leading to the belief they have a residual CVD risk that cannot be attenuated by conventional treatment. All these conclusions disregard the facts that the correlation between BP level and CVD risk is stronger for ambulatory than clinic BP and that the BP-lowering efficacy and effects on the 24-h BP pattern of different classes of hypertension medications exhibit statistically and clinically significant treatment-time (morning versus evening) differences. Accordingly, we evaluated the potential differential administration-time-dependent effects on CVD risk of the various classes of hypertension medications and the number of them used for therapy in the MAPEC (Monitorizacion Ambulatoria para Prediccion de Eventos Cardiovasculares, i.e., Ambulatory Blood Pressure Monitoring for Prediction of Cardiovascular Events) study, a prospective, open-label, blinded-endpoint trial on 2156 hypertensive patients (1044 men/1112 women), 55.6 +/- 13.6 (mean +/- SD) yrs of age, randomized to ingest all prescribed once-a-day hypertension medications upon awakening or the entire daily dose of >= 1 of them at bedtime. Ambulatory BP was measured for 48 h at baseline, and again annually or more frequently (quarterly) when adjustment of treatment was necessary to achieve ambulatory, i.e., awake and asleep, BP control. CVD risk according to the number and classes of medications used at the final evaluation was calculated by comparison with that of 734 normotensive subjects who were identically followed and remained untreated. After a median follow-up of 5.6 yrs, CVD risk of hypertensive patients randomized to ingest all medications upon awakening was progressively higher with increase in the number of medications (adjusted hazard ratio [HR]: 1.75, 2.26, 3.02, and 4.18 in patients treated with 1, 2, 3, and >= 4 medications daily, respectively; p<.001 compared with normotensive subjects). CVD risk was markedly lower in patients ingesting >= 1 medications at bedtime (HR: .35, 1.45, .94, and 2.28 with 1, 2, 3, and >= 4 medications daily, respectively), and even lower in patients ingesting all medications at bedtime (HR: .35, .39, .87, and .79 with 1, 2, 3, and >= 4 medications daily, respectively). Patients ingesting >= 1 medications at bedtime evidenced significantly lower CVD risk than those ingesting all medications upon awakening, independent of class. Greater benefits were observed for bedtime compared with awakening treatment with angiotensin-II receptor blockers (ARBs) (HR: .29 [95% confidence interval, CI .17-.51]; p<.001) and calcium channel blockers (HR: .46 [95% CI: .31-.69]; p<.001). CVD risk was similar for all six classes of tested hypertension medications in patients randomized to ingest all of them upon awakening. Among patients randomized to ingest >= 1 medications at bedtime, however, ARBs were associated with significantly lower HR of CVD events than ingestion of any other class of medication also at bedtime (p<.017). We document significantly reduced CVD risk among hypertensive patients ingesting medications at bedtime, independent of the number of hypertension medications required to achieve proper ambulatory BP control. These findings challenge the current belief of residual CVD risk, as a bedtime-treatment regimen of current hypertension medications, even in risk-high patients, can reduce such risk. (Author correspondence: rhermida@uvigo.es)