The aim of this study was to compare the risk of cardiovascular disease (CVD) – nonfatal acute myocardial infarction (AMI) or stroke – at blood pressure levels that meet current recommendations with risk at lower levels, particularly in older patients.
We identified patients with hypertension aged 40–90 years from a primary care register. Patients with a history of cancer, diabetes mellitus or CVD were excluded. Patients were divided into age groups (40–75 and 76–90), and four groups of SBP 110–129, 130–139 (reference), 140–149 and ≥150 mmHg. We used the Kaplan–Meier estimator to study incidence of AMI, stroke and a composite of the two. Cox proportional-hazards regression was used to estimate hazard ratios for outcomes.
We included 31 704 patients: 26 663 were 40–75 years old and 5041 were 76–90 years old. Mean follow-up was 2 years. Although no significant differences in risk of any outcome were found in the younger group, low blood pressure was associated with the lowest risk in the older group. Older patients in the 110–129 mmHg group had a lower incidence of CVD (15.9/1000 vs. 25.3/1000 person-years) than the reference group. After adjustment for covariates, the hazard ratio of CVD in older patients in the 110–129 mmHg group compared with the reference group was 0.60 (95% confidence interval 0.40–0.92).
Blood pressure levels lower than those currently recommended are not harmful among older patients. The association between lower SBP and lesser risk of CVD may instead suggest a beneficial effect of lower SBP.
aDepartment of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg
bNärhälsan Research and Development Center, Skaraborg Primary Care, Skövde
cCentre of Registers. Västra Götaland County
dSection for Emergency Medicine, Department of Internal Medicine, Sahlgrenska University Hospital
eSahlgrenska University Hospital/Östra
fDepartment of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
Correspondence to Johan-Emil Bager, Section for Emergency Medicine, Department of Internal Medicine, Sahlgrenska University Hospital, Gröna Stråket 4, 413 45 Gothenburg, Sweden. Tel: +46 31 343 98 41; fax: +46 31 82 86 21; e-mail: firstname.lastname@example.org
Abbreviations: ACA, American College of Cardiology; AHA, American Heart Association; ATC, Anatomic Therapeutic Chemical; BP, blood pressure; CHD, coronary heart disease; CVD, cardiovascular disease; ESC, European Society of Cardiology; ESH, European Society of Hypertension; HYVET, The Hypertension in the Very Elderly Trial; ICD-10, International Classification of Diseases, 10th revision; JATOS, Japanese Trial to Assess Optimal Systolic Blood Pressure in Elderly Hypertensive Patients; LDL, low-density lipoprotein; LISA, the longitudinal integration database for health insurance and labour market studies; QregPV, The regional primary care quality register in Västra Götaland; RAAS, renin–angiotensin–aldosterone system; RCT, randomized controlled trial; SD, standard deviation; SHEP, Systolic Hypertension in Elderly Program; SPRINT, Systolic Blood Pressure Intervention Trial; STOP, Swedish Trial in Old Patients with Hypertension; VALISH, Valsartan in Elderly Isolated Systolic Hypertension Study; VEGA, The regional administrative healthcare database of Västra Götaland
Received 18 November, 2018
Revised 30 April, 2019
Accepted 1 May, 2019
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