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):2305-14. doi: 10.1097/HJH.0000000000000380.
Randomized controlled trials (RCTs) of blood pressure (BP) lowering lend themselves to be meta-analyzed to help providing evidence-based recommendations for hypertension treatment.
To investigate whether relative or absolute risk reductions increase at increasing levels of baseline cardiovascular risk and whether BP-lowering treatment should be addressed to patients in risk categories promising larger absolute treatment benefits.
Sixty-eight RCTs of intentional and nonintentional BP lowering were classified in four strata of increasing average 10-year incidence of cardiovascular death in the placebo or less active treatment group: low-to-moderate risk (<5%; 23 RCTs, 81,675 individuals), high risk (5% to <10%; 11 RCTs, 46,162 individuals), very high risk (10% to <20%; 19 RCTs, 91,152 individuals), and very very high risk (≥20%; 16 RCTs, 26,881 individuals). Risk ratios and 95% confidence intervals (CIs; random-effects model) standardized to 10/5 mmHg SBP/DBP reduction, absolute risk reduction, and residual risk of seven major fatal/nonfatal outcomes were calculated. Relative and absolute risk reductions in the cardiovascular risk strata were compared by the trend analysis, residual risk by calculating odds ratio (OR) relative to low-to-moderate risk.
Relative reductions of all outcomes did not differ in the risk strata, but absolute reductions significantly increased with increasing cardiovascular risk (P for trend <0.001 except for CHD): a 10/5 mmHg SBP/DBP reduction reduced the incidence of major cardiovascular events by 7 (95% CI 3-10), 30 (9-50), 56 (35-76), and 87 (62-112) events every 1000 patients treated 5 years, with increasing cardiovascular risk. However, also residual risk significantly (P < 0.001) increased with increasing cardiovascular risk [up to an OR 9.43 (8.60-10.35) for cardiovascular death]. The increase in residual risk with increasing level of cardiovascular risk persisted when RCTs with average initial age at least 65 years were excluded, and mean ages at the different cardiovascular risk levels were comparable.
BP-lowering treatment induces greater absolute risk reductions the higher the cardiovascular risk level, but a higher risk level is also associated with higher absolute residual risk, independent of age. Whereas reserving antihypertensive treatment to high-risk hypertensive patients maximizes the cost-benefit ratio, only treatment of low-to-moderate risk hypertensive patients may prevent the increasing number of treatment failures when treatment is initiated at higher risk.
降压的随机对照试验（RCT）适合进行荟萃分析，以帮助为高血压治疗提供循证建议。
探讨随着基线心血管风险水平升高，相对风险降低或绝对风险降低是否增加，以及降压治疗是否应针对有望获得更大绝对治疗益处的风险类别患者。
68项有意和无意降压的RCT被分为四个层次，安慰剂或活性较低治疗组中10年心血管死亡平均发生率递增：低至中度风险（<5%；23项RCT，81675例个体）、高风险（5%至<10%；11项RCT，46162例个体）、非常高风险（10%至<20%；19项RCT，91152例个体）和非常非常高风险（≥20%；16项RCT，26881例个体）。计算了标准化为收缩压/舒张压降低10/5 mmHg的风险比和95%置信区间（CIs；随机效应模型）、绝对风险降低以及七种主要致命/非致命结局的残余风险。通过趋势分析比较心血管风险层次中的相对和绝对风险降低，通过计算相对于低至中度风险的比值比（OR）来比较残余风险。
所有结局的相对降低在风险层次中无差异，但绝对降低随心血管风险增加而显著增加（除冠心病外，趋势P<0.001）：收缩压/舒张压降低10/5 mmHg使每1000例接受5年治疗的患者中主要心血管事件的发生率分别降低7例（95%CI 3 - 10）、30例（9 - 50）、56例（35 - 76）和87例（62 - 112），心血管风险增加。然而，残余风险也随心血管风险增加而显著增加（P<0.001）[心血管死亡的OR高达9.43（8.60 - 10.35）]。排除平均初始年龄至少65岁的RCT后，残余风险随心血管风险水平增加的情况仍然存在，且不同心血管风险水平的平均年龄具有可比性。
心血管风险水平越高，降压治疗带来的绝对风险降低越大，但较高的风险水平也与较高的绝对残余风险相关，与年龄无关。虽然将降压治疗保留给高危高血压患者可使成本效益比最大化，但只有治疗低至中度风险的高血压患者才能在高风险时开始治疗时防止治疗失败数量的增加。
