Thomopoulos Costas, Parati Gianfranco, Zanchetti Alberto
aDepartment of Cardiology, Helena Venizelou Hospital, Athens, Greece bDepartment of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Istituto Auxologico Italiano IRCCS cDepartment of Health Sciences, University of Milan Bicocca dScientific Direction, Istituto Auxologico Italiano IRCCS eCentro Interuniversitario di Fisiologia Clinica e Ipertensione, University of Milan, Milan, Italy.
J Hypertens. 2014 Dec;32(12):2296-304. doi: 10.1097/HJH.0000000000000379.
Relevant clinical questions not approached by randomized controlled trials (RCTs) of blood pressure (BP)-lowering treatment can be explored by meta-analyses stratified by clinical criteria.
Investigating whether all grades of hypertension benefit from BP-lowering treatment and which are the target BP levels to maximize outcome reduction.
Of the 68 RCTs of intentional and nonintentional BP-lowering, those without baseline antihypertensive drugs were stratified by the average baseline SBP and DBP (hypertension grades 1, 2, and 3). RCTs with or without baseline treatment were considered for investigating the effects of mean achieved SBP/DBP across three SBP cutoffs and two DBP cutoffs. Risk ratios (RR) and 95% confidence interval (CI) (random-effects model), standardized to 10/5 mmHg SBP/DBP reduction, and absolute risk reductions of seven fatal and nonfatal outcomes were calculated. Differences between relative and absolute risk reductions in the different strata of baseline or achieved SBP/DBP were evaluated by trend or heterogeneity analyses.
In 32 RCTs (104,359 individuals), significant outcome reductions were found independently of the hypertension grade, with no trend toward risk ratio changes with increasing baseline BP. A secondary analysis limited to RCTs on grade 1 hypertension at low-to-moderate risk showed significant outcome reductions [risk ratio: stroke 0.33 (0.11-0.98), coronary events 0.68 (0.48-0.95), and death 0.53 (0.35-0.80)]. In 32 RCTs (128,232 individuals), relative and absolute outcome reductions were significant for the SBP differences across 150 and 140 mmHg cutoffs. Below 130 mmHg, only stroke and all-cause death were significantly reduced. Absolute outcome reduction showed a significant trend to decrease, the lower the SBP cutoff considered. In 29 RCTs (107,665 individuals), outcomes were significantly reduced across DBP cutoffs of 90 and 80 mmHg. After excluding RCTs with baseline DBP less than 90 mmHg, only stroke reduction was significant at achieved DBP less than 80 mmHg.
Meta-analyses favor BP-lowering treatment even in grade 1 hypertension at low-to-moderate risk, and lowering SBP/DBP to less than 140/90 mmHg. Achieving less than 130/80 mmHg appears safe, but only adds further reduction in stroke.
通过按临床标准分层的荟萃分析，可以探讨降压治疗的随机对照试验（RCT）未涉及的相关临床问题。
研究所有级别的高血压是否都能从降压治疗中获益，以及哪些目标血压水平能最大程度降低结局风险。
在68项有意和无意降压的RCT中，将那些无基线抗高血压药物的研究按平均基线收缩压（SBP）和舒张压（DBP）（高血压1级、2级和3级）进行分层。考虑有或无基线治疗的RCT，以研究三个SBP临界值和两个DBP临界值时平均达到的SBP/DBP的影响。计算风险比（RR）和95%置信区间（CI）（随机效应模型），标准化为SBP/DBP降低10/5 mmHg，并计算七种致命和非致命结局的绝对风险降低值。通过趋势或异质性分析评估基线或达到的SBP/DBP不同分层中相对和绝对风险降低的差异。
在32项RCT（104,359例个体）中，发现结局显著降低，与高血压级别无关，且随着基线血压升高，风险比无变化趋势。一项仅限于低至中度风险的1级高血压RCT的二次分析显示结局显著降低[风险比：卒中0.33（0.11 - 0.98），冠状动脉事件0.68（0.48 - 0.95），死亡0.53（0.35 - 0.80）]。在32项RCT（128,232例个体）中，SBP差异在150和140 mmHg临界值时，相对和绝对结局降低均显著。低于130 mmHg时，仅卒中和全因死亡显著降低。考虑的SBP临界值越低，绝对结局降低显示出显著的下降趋势。在29项RCT（107,665例个体）中，可以看出DBP临界值在90和80 mmHg时结局显著降低。排除基线DBP低于90 mmHg的RCT后，仅在达到的DBP低于80 mmHg时卒中降低显著。
荟萃分析支持即使是低至中度风险的1级高血压也应进行降压治疗，并将SBP/DBP降至低于140/90 mmHg。降至低于130/80 mmHg似乎是安全的，但仅能进一步降低卒中风险。
