Strategies to identify patients for antihypertensive treatment
Authors: Thomas Kahan
Journal: The Lancet (2019)

Elevated blood pressure is the major risk factor for disease and premature death globally, and the association between blood pressure and fatal cardiovascular complications is strong.1Rapsomaniki E Timmis A George J et al.Blood pressure and incidence of twelve cardiovascular diseases: lifetime risks, healthy life-years lost, and age-specific associations in 1·25 million people.Lancet. 2014; 383: 1899-1911Summary Full Text Full Text PDF PubMed Scopus (968) Google Scholar, 2Stanaway JD Afshin A Gakidou E et al.Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017.Lancet. 2018; 392: 1923-1994Summary Full Text Full Text PDF PubMed Scopus (2421) Google Scholar Antihypertensive treatment can reduce cardiovascular morbidity and all-cause mortality and, supported by evidence summarised in 2018,3Reboussin DM Allen NB Griswold ME et al.Systematic review for the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.J Am Coll Cardiol. 2018; 71: 2176-2198PubMed Google Scholar lower target blood pressure values have been introduced into existing recommendations on the management of hypertension.4Whelton PK Carey RM Aronow WS et al.2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.J Am Coll Cardiol. 2018; 71: e127-e248Crossref PubMed Scopus (2564) Google Scholar, 5Williams B Mancia G Spiering W et al.2018 ESC/ESH guidelines for the management of arterial hypertension.Eur Heart J. 2018; 39: 3021-3104Crossref PubMed Scopus (4860) Google Scholar However, the absolute benefit of antihypertensive treatment in reducing cardiovascular events is determined by the overall cardiovascular risk of the individual. Therefore, a strategy to identify patients to be offered antihypertensive treatment based on cardiovascular risk might be superior to a strategy that offers treatment on the basis of threshold blood pressure values alone. In The Lancet, Emily Herrett and colleagues6Herrett E Gadd S Jackson R et al.Eligibility and subsequent burden of cardiovascular disease of four strategies for blood pressure-lowering treatment: a retrospective cohort study.Lancet. 2019; (published online July 25.)http://dx.doi.org/10.1016/S0140-6736(19)31359-5Summary Full Text Full Text PDF PubMed Scopus (23) Google Scholar report on the eligibility and outcomes of offering antihypertensive treatment on the basis of cardiovascular risk compared with those of strategies relying on blood pressure level. This retrospective cohort study in the UK collected information from primary care, diagnoses, and procedures from hospital-based care, and mortality data for 1 222 670 people (57% women) aged 30–79 years with no previous cardiovascular disease. Herrett and colleagues compared four strategies to define treatment eligibility: a blood pressure of 140/90 mm Hg or higher alone, existing (2011) and proposed (2019) UK National Institute for Health and Care Excellence (NICE) guidelines on the management of hypertension, and an absolute risk strategy based on a predicted 10-year cardiovascular event risk (according to QRISK2) of 10% or greater. The primary outcome was a first cardiovascular diagnosis of coronary artery disease or cerebrovascular disease. Median age at entry was 51 years (IQR 41–62), blood pressure was 129/78 mm Hg, and 18% of participants were on antihypertensive treatment. During a median follow-up of 4·3 years (IQR 2·5–5·2), 7·1 cardiovascular events per 1000 person-years were diagnosed. The proportion of patients eligible for treatment was higher with a strategy based on blood pressure alone (39·4%) than with strategies based on NICE 2011 (22·2%) and NICE 2019 (26·8%) guidelines or with a risk-based strategy alone (29·3%). More importantly, however, the efficiencies of the strategies were different: cardiovascular event rates in patients eligible for treatment with each strategy were 11·4 per 1000 person-years (95% CI 11·3–11·6) with a blood pressure strategy, 15·2 (15·0–15·5) with NICE 2011 guidelines, 14·9 (14·7–15·1) with NICE 2019 guidelines, and 16·9 (16·7–17·1) with a risk-based strategy. Therefore, a strategy based on blood pressure alone would require 38 patients treated for 10 years to avoid one event. Treatment based on NICE 2011 guidelines would require 28 and NICE 2019 guidelines 29 treated patients, whereas an absolute risk strategy would require 27 patients treated for 10 years to avoid one event. Therefore, these results suggest that, with a similar efficiency, a strategy based on absolute risk would prevent substantially more people from incident cardiovascular disease than strategies based on NICE 2011 or NICE 2019 guidelines. Herrett and colleagues' results add evidence favouring a strategy where offering antihypertensive treatment on the basis of cardiovascular risk might be superior to treating people on the basis of blood pressure values alone.7Sundström J Arima H Woodward M et al.Blood pressure-lowering treatment based on cardiovascular risk: a meta-analysis of individual patient data.Lancet. 2014; 384: 591-598Summary Full Text Full Text PDF PubMed Scopus (8) Google Scholar, 8Karmali KN Lloyd-Jones DM van der Leeuw J et al.Blood pressure-lowering treatment strategies based on cardiovascular risk versus blood pressure: a meta-analysis of individual participant data.PLoS Med. 2018; 15e1002538Crossref PubMed Scopus (52) Google Scholar Nevertheless, we should always recommend lifestyle modifications and consider drug treatment (when appropriate) for dyslipidaemia and glucose intolerance, as well as support smoking cessation to reduce cardiovascular risk. Notably, only 43–70% of the patients eligible for treatment under any of the four strategies received antihypertensive treatment, and only half of those treated achieved blood pressure lower than 140/90 mm Hg. Therefore, and corroborating the findings of other studies,4Whelton PK Carey RM Aronow WS et al.2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.J Am Coll Cardiol. 2018; 71: e127-e248Crossref PubMed Scopus (2564) Google Scholar, 5Williams B Mancia G Spiering W et al.2018 ESC/ESH guidelines for the management of arterial hypertension.Eur Heart J. 2018; 39: 3021-3104Crossref PubMed Scopus (4860) Google Scholar adherence by care providers to guideline recommendations to treat blood pressure to target levels needs to be improved, along with treatment strategies based on cardiovascular risk. Some limitations of Herrett and colleagues' study should be considered. First, a target blood pressure of 130/80 mm Hg or lower in patients aged 65 years or younger is recommended, but the additional benefits of a blood pressure lower than 120/70 mm Hg is less certain and might associate with an increased cardiovascular risk.4Whelton PK Carey RM Aronow WS et al.2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.J Am Coll Cardiol. 2018; 71: e127-e248Crossref PubMed Scopus (2564) Google Scholar, 5Williams B Mancia G Spiering W et al.2018 ESC/ESH guidelines for the management of arterial hypertension.Eur Heart J. 2018; 39: 3021-3104Crossref PubMed Scopus (4860) Google Scholar Furthermore, the evidence supporting a reduction in cardiovascular events by starting antihypertensive treatment at blood pressure values lower than 140/90 mm Hg is unclear, particularly in people without high cardiovascular risk and in older individuals.4Whelton PK Carey RM Aronow WS et al.2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.J Am Coll Cardiol. 2018; 71: e127-e248Crossref PubMed Scopus (2564) Google Scholar, 5Williams B Mancia G Spiering W et al.2018 ESC/ESH guidelines for the management of arterial hypertension.Eur Heart J. 2018; 39: 3021-3104Crossref PubMed Scopus (4860) Google Scholar A risk-based strategy would also make people with normal or slightly elevated blood pressure eligible for antihypertensive treatment. Second, the prevalence of hypertension increases sharply with age, and the number of old and very old people treated for hypertension is high.9Wallentin F Wettermark B Kahan T Current antihypertensive drug therapy in Sweden in relation to gender, age, and comorbidity.J Clin Hypertens. 2018; 20: 106-114Crossref Scopus (17) Google Scholar Additionally, among treated patients with hypertension aged 90 years or older, a third of women and a fourth of men are free of cardiovascular comorbidity, diabetes, or chronic obstructive pulmonary disease.9Wallentin F Wettermark B Kahan T Current antihypertensive drug therapy in Sweden in relation to gender, age, and comorbidity.J Clin Hypertens. 2018; 20: 106-114Crossref Scopus (17) Google Scholar However, Herrett and colleagues did not investigate people aged 80 years or older, in whom the possible benefits or harms of a risk-based treatment strategy remain to be assessed. Third, the study used QRISK210Hippisley-Cox J Coupland C Vinogradova Y et al.Predicting cardiovascular risk in England and Wales: prospective derivation and validation of QRISK2.BMJ. 2008; 336: 1475-1482Crossref PubMed Scopus (1008) Google Scholar for the strategy based on cardiovascular risk. Other recommended risk score systems used in Europe, such as the Systematic Coronary Risk Evaluation (SCORE)11Piepoli MF Hoes AW Agewall S et al.2016 European guidelines on cardiovascular disease prevention in clinical practice: the Sixth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (constituted by representatives of 10 societies and by invited experts): developed with the special contribution of the European Association for Cardiovascular Prevention & Rehabilitation (EACPR).Eur J Prev Cardiol. 2016; 37: 2315-2381Google Scholar and the SCORE OP (older persons),12Cooney MT Selmer R Lindman A Cardiovascular risk estimation in older persons: SCORE O.P.Eur J Prev Cardiol. 2016; 23: 1093-1103Crossref PubMed Scopus (111) Google Scholar use less background information, calculate a 10-year cardiovascular mortality risk, or both. The use of these risk scores might not yield results similar to those of this study. However, Herrett and colleagues' findings of antihypertensive treatment eligibility based on cardiovascular risk being superior to eligibility based on blood pressure alone would most likely persist. In conclusion, the work of Herrett and colleagues shows the importance of assessing cardiovascular risk in the management of hypertension, and suggests that a strategy to offer antihypertensive therapy based on absolute cardiovascular risk might prevent more cardiovascular disease than a strategy based on blood pressure alone. I report research grants to Karolinska Institute from Amgen, Medtronic, ReCor Medical, and Regeneron Pharmaceuticals, all outside the area of work commented on here. Eligibility and subsequent burden of cardiovascular disease of four strategies for blood pressure-lowering treatment: a retrospective cohort studyA cardiovascular risk-based strategy (QRISK2 ≥10%) could prevent over a third more cardiovascular disease events than the 2011 NICE guideline and a fifth more than the 2019 NICE guideline, with similar efficiency regarding number treated per event avoided. Full-Text PDF Open Access