Automatic data extraction from 24 hour blood pressure measurement reports of a large multicenter clinical trial

Ambulatory blood pressure after 12 weeks of quadruple combination of quarter doses of blood pressure medication vs. standard medication

BACKGROUND

A combination of four ultra-low-dose blood pressure (BP) medications lowered office BP more effectively than initial monotherapy in the QUARTET trial. The effects on average ambulatory BP changes at 12 weeks have not yet been reported in detail.

METHODS

Adults with hypertension who were untreated or on monotherapy were eligible for participation. Overall, 591 participants were randomized to either the quadpill (irbesartan 37.5 mg, amlodipine 1.25 mg, indapamide 0.625 mg, and bisoprolol 2.5 mg) or monotherapy control (irbesartan 150 mg). The difference in 24-h, daytime, and night-time systolic and diastolic ambulatory BP at 12 weeks along further metrics were predefined secondary outcomes.

RESULTS

Of 576 participants, 289 were randomized to the quadpill group and 287 to the monotherapy group. At 12 weeks, mean 24-h ambulatory SBP and DBP were 7.7 [95% confidence interval (95% CI) 9.6-5.8] and 5.3 (95% CI: 6.5-4.1) mmHg lower in the quadpill vs. monotherapy group ( P  < 0.001 for both). Similar reductions in the quadpill group were observed for daytime (8.1/5.7 mmHg lower) and night-time (6.3/4.0 mmHg lower) BP at 12 weeks (all P  < 0.001) compared to monotherapy. The rate of BP control (24-h average BP < 130/80 mmHg) at 12 weeks was higher in the quadpill group (77 vs. 50%; P  < 0.001). The reduction in BP load was also more pronounced with the quadpill.

CONCLUSION

A quadruple quarter-dose combination compared with monotherapy resulted in greater ambulatory BP lowering across the entire 24-h period with higher ambulatory BP control rates and reduced BP variability at 12 weeks. These findings further substantiate the efficacy of an ultra-low-dose quadpill-based BP lowering strategy.

Impact of various night-time period definitions on nocturnal ambulatory blood pressure

BACKGROUND

Several definitions of night-time BP exist for the calculation of nocturnal blood pressure (BP) based on 24-h BP measurements. How much these methods differ regarding the resulting nocturnal blood pressure values, under which circumstances these differences become clinically meaningful, and under which circumstances diary-adjusted measurements should be used preferentially remains uncertain.

METHODS

Data of 512 24-h BP recordings were analysed regarding differences in nocturnal BP based on three alternative definitions of night-time: 2300-0700 h, 0100-0500 h, and diary-adjusted measures.

RESULTS

Mean systolic nocturnal BP between 2300-0700 h was 2.5 mmHg higher than between 0100 and 0500 h and 1.6 mmHg higher than diary adjusted estimates. Up to 38.3% of individuals showed BP differences of more than 5 mmHg when comparing temporal definitions of night-time, resulting in significant proportions of individuals being re-classified as hypertensive. When diary-derived sleeping patterns differed by less than 2 h from the 2300 to 0700 h fixed time definition, mean BP discrepancies remained below 3 mmHg. Absolute time discrepancies between diary and 2300-0700 h fixed time definition of 2-4, 4-8 or at least 8 h led to SBP/DBP differences of 4.1/3.1, 6.8/6.1, and 14.5/9.1mmHg, respectively.

CONCLUSION

Average differences of nocturnal BP between varying definitions in study/cohort data are small and would be of limited relevance in many settings. However, substantial differences can be observed in individual cases, which may affect clinical decision-making in specific patients. In patients whose sleeping patterns differs by more than 2 h from defined fixed night-times, diaries should be used for adjustment.