Risk of post-pregnancy hypertension in women with a history of hypertensive disorders of pregnancy: nationwide cohort study

Objectives To determine how soon after delivery the risk of post-pregnancy hypertension increases in women with hypertensive disorders of pregnancy and how the risk evolves over time.

Design Nationwide register based cohort study.

Setting Denmark.

Populations 482 972 primiparous women with a first live birth or stillbirth between 1995 and 2012 (cumulative incidence analyses), and 1 025 118 women with at least one live birth or stillbirth between 1978 and 2012 (Cox regression analyses).

Main outcome measures 10 year cumulative incidences of post-pregnancy hypertension requiring treatment with prescription drugs, and hazard ratios estimated using Cox regression.

Results Of women with a hypertensive disorder of pregnancy in a first pregnancy in their 20s, 14% developed hypertension in the first decade post partum, compared with 4% of women with normotensive first pregnancies in their 20s. The corresponding percentages for women with a first pregnancy in their 40s were 32% and 11%, respectively. In the year after delivery, women with a hypertensive disorder of pregnancy had 12-fold to 25-fold higher rates of hypertension than did women with a normotensive pregnancy. Rates in women with a hypertensive disorder of pregnancy were threefold to 10-fold higher 1-10 years post partum and remained twice as high even 20 or more years later.

Conclusions The risk of hypertension associated with hypertensive disorders of pregnancy is high immediately after an affected pregnancy and persists for more than 20 years. Up to one third of women with a hypertensive disorder of pregnancy may develop hypertension within a decade of an affected pregnancy, indicating that cardiovascular disease prevention in these women should include blood pressure monitoring initiated soon after pregnancy.

Reference: BMJ 2017;358:j3078

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Lifestyle in progression from hypertensive disorders of pregnancy to chronic hypertension in Nurses’ Health Study II: observational cohort study

Objectives To study the association between lifestyle risk factors and chronic hypertension by history of hypertensive disorders of pregnancy (HDP: gestational hypertension and pre-eclampsia) and investigate the extent to which these risk factors modify the association between HDP and chronic hypertension.

Design Prospective cohort study.

Setting Nurses’ Health Study II (1991-2013).

Participants 54 588 parous women aged 32 to 59 years with data on reproductive history and without previous chronic hypertension, stroke, or myocardial infarction.

Main outcome measure Chronic hypertension diagnosed by a physician and indicated through nurse participant self report. Multivariable Cox proportional hazards models were used to investigate the development of chronic hypertension contingent on history of HDP and four lifestyle risk factors: post-pregnancy body mass index, physical activity, adherence to the Dietary Approaches to Stop Hypertension (DASH) diet, and dietary sodium/potassium intake. Potential effect modification (interaction) between each lifestyle factor and previous HDP was evaluated with the relative excess risk due to interaction.

Results 10% (n=5520) of women had a history of HDP at baseline. 13 971 cases of chronic hypertension occurred during 689 988 person years of follow-up. Being overweight or obese was the only lifestyle factor consistently associated with higher risk of chronic hypertension. Higher body mass index, in particular, also increased the risk of chronic hypertension associated with history of HDP (relative excess risk due to interaction P<0.01 for all age strata). For example, in women aged 40-49 years with previous HDP and obesity class I (body mass index 30.0-34.9), 25% (95% confidence interval 12% to 37%) of the risk of chronic hypertension was attributable to a potential effect of obesity that was specific to women with previous HDP. There was no clear evidence of effect modification by physical activity, DASH diet, or sodium/potassium intake on the association between HDP and chronic hypertension.

Conclusion This study suggests that the risk of chronic hypertension after HDP might be markedly reduced by adherence to a beneficial lifestyle. Compared with women without a history of HDP, keeping a healthy weight seems to be especially important with such a history.

Reference:  BMJ 2017;358:j3024

The Dietary Approaches to Stop Hypertension (DASH) diet, Western diet, and risk of gout in men: prospective cohort study

Objective To prospectively examine the relation between the Dietary Approaches to Stop Hypertension (DASH) and Western diets and risk of gout (ie, the clinical endpoint of hyperuricemia) in men.

Design Prospective cohort study.

Setting The Health Professionals Follow-up Study.

Participants 44 444 men with no history of gout at baseline. Using validated food frequency questionnaires, each participant was assigned a DASH dietary pattern score (based on high intake of fruits, vegetables, nuts and legumes, low fat dairy products, and whole grains, and low intake of sodium, sweetened beverages, and red and processed meats) and a Western dietary pattern score (based on high intake of red and processed meats, French fries, refined grains, sweets, and desserts).

Main outcome measure Risk of incident gout meeting the preliminary American College of Rheumatology survey criteria for gout, adjusting for potential confounders, including age, body mass index, hypertension, diuretic use, and alcohol intake.

Results During 26 years of follow-up, 1731 confirmed cases of incident gout were documented. A higher DASH dietary pattern score was associated with a lower risk for gout (adjusted relative risk for extreme fifths 0.68, 95% confidence interval 0.57 to 0.80, P value for trend <0.001). In contrast, a higher Western dietary pattern score was associated with an increased risk for gout (1.42, 1.16 to 1.74, P=0.005).

Conclusion The DASH diet is associated with a lower risk of gout, suggesting that its effect of lowering uric acid levels in individuals with hyperuricemia translates to a lower risk of gout. Conversely, the Western diet is associated with a higher risk of gout. The DASH diet may provide an attractive preventive dietary approach for men at risk of gout.

Reference: BMJ 2017;357:j1794

Quarter-dose quadruple combination therapy for initial treatment of hypertension: placebo-controlled, crossover, randomised trial and systematic review

Background

Globally, most patients with hypertension are treated with monotherapy, and control rates are poor because monotherapy only reduces blood pressure by around 9/5 mm Hg on average. There is a pressing need for blood pressure-control strategies with improved efficacy and tolerability. We aimed to assess whether ultra-low-dose combination therapy could meet these needs.

Methods

We did a randomised, placebo-controlled, double-blind, crossover trial of a quadpill—a single capsule containing four blood pressure-lowering drugs each at quarter-dose (irbesartan 37·5 mg, amlodipine 1·25 mg, hydrochlorothiazide 6·25 mg, and atenolol 12·5 mg). Participants with untreated hypertension were enrolled from four centres in the community of western Sydney, NSW, Australia, mainly by general practitioners. Participants were randomly allocated by computer to either the quadpill or matching placebo for 4 weeks; this treatment was followed by a 2-week washout, then the other study treatment was administered for 4 weeks. Study staff and participants were unaware of treatment allocations, and masking was achieved by use of identical opaque capsules. The primary outcome was placebo-corrected 24-h systolic ambulatory blood pressure reduction after 4 weeks and analysis was by intention to treat. We also did a systematic review of trials evaluating the efficacy and safety of quarter-standard-dose blood pressure-lowering therapy against placebo. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12614001057673. The trial ended after 1 year and this report presents the final analysis.

Findings

Between November, 2014, and December, 2015, 55 patients were screened for our randomised trial, of whom 21 underwent randomisation. Mean age of participants was 58 years (SD 11) and mean baseline office and 24-h systolic and diastolic blood pressure levels were 154 (14)/90 (11) mm Hg and 140 (9)/87 (8) mm Hg, respectively. One individual declined participation after randomisation and two patients dropped out for administrative reasons. The placebo-corrected reduction in systolic 24-h blood pressure with the quadpill was 19 mm Hg (95% CI 14–23), and office blood pressure was reduced by 22/13 mm Hg (p<0·0001). During quadpill treatment, 18 (100%) of 18 participants achieved office blood pressure less than 140/90 mm Hg, compared with six (33%) of 18 during placebo treatment (p=0·0013). There were no serious adverse events and all patients reported that the quadpill was easy to swallow. Our systematic review identified 36 trials (n=4721 participants) of one drug at quarter-dose and six trials (n=312) of two drugs at quarter-dose, against placebo. The pooled placebo-corrected blood pressure-lowering effects were 5/2 mm Hg and 7/5 mm Hg, respectively (both p<0·0001), and there were no side-effects from either regimen.

Interpretation

The findings of our small trial in the context of previous randomised evidence suggest that the benefits of quarter-dose therapy could be additive across classes and might confer a clinically important reduction in blood pressure. Further examination of the quadpill concept is needed to investigate effectiveness against usual treatment options and longer term tolerability.

Funding

National Heart Foundation, Australia; University of Sydney; and National Health and Medical Research Council of Australia.

The Lancet, Volume 389, No. 10073, p1035–1042, 11 March 2017

Effects of intensive blood pressure lowering on cardiovascular and renal outcomes: updated systematic review and meta-analysis

Background

Recent hypertension guidelines have reversed previous recommendations for lower blood pressure targets in high-risk patients, such as those with cardiovascular disease, renal disease, or diabetes. This change represents uncertainty about whether more intensive blood pressure-lowering strategies are associated with greater reductions in risk of major cardiovascular and renal events. We aimed to assess the efficacy and safety of intensive blood pressure-lowering strategies.

Methods

For this updated systematic review and meta-analysis, we systematically searched MEDLINE, Embase, and the Cochrane Library for trials published between Jan 1, 1950, and Nov 3, 2015. We included randomised controlled trials with at least 6 months’ follow-up that randomly assigned participants to more intensive versus less intensive blood pressure-lowering treatment, with different blood pressure targets or different blood pressure changes from baseline. We did not use any age or language restrictions. We did a meta-analysis of blood pressure reductions on relative risk (RR) of major cardiovascular events (myocardial infarction, stroke, heart failure, or cardiovascular death, separately and combined), and non-vascular and all-cause mortality, end-stage kidney disease, and adverse events, as well as albuminuria and progression of retinopathy in trials done in patients with diabetes.

Findings

We identified 19 trials including 44 989 participants, in whom 2496 major cardiovascular events were recorded during a mean 3·8 years of follow-up (range 1·0–8·4 years). Our meta-analysis showed that after randomisation, patients in the more intensive blood pressure-lowering treatment group had mean blood pressure levels of 133/76 mm Hg, compared with 140/81 mm Hg in the less intensive treatment group. Intensive blood pressure-lowering treatment achieved RR reductions for major cardiovascular events (14% [95% CI 4–22]), myocardial infarction (13% [0–24]), stroke (22% [10–32]), albuminuria (10% [3–16]), and retinopathy progression (19% [0–34]). However, more intensive treatment had no clear effects on heart failure (15% [95% CI −11 to 34]), cardiovascular death (9% [–11 to 26]), total mortality (9% [–3 to 19]), or end-stage kidney disease (10% [–6 to 23]). The reduction in major cardiovascular events was consistent across patient groups, and additional blood pressure lowering had a clear benefit even in patients with systolic blood pressure lower than 140 mm Hg. The absolute benefits were greatest in trials in which all enrolled patients had vascular disease, renal disease, or diabetes. Serious adverse events associated with blood pressure lowering were only reported by six trials and had an event rate of 1·2% per year in intensive blood pressure-lowering group participants, compared with 0·9% in the less intensive treatment group (RR 1·35 [95% CI 0·93–1·97]). Severe hypotension was more frequent in the more intensive treatment regimen (RR 2·68 [1·21–5·89], p=0·015), but the absolute excess was small (0·3% vs 0·1% per person-year for the duration of follow-up).

Interpretation

Intensive blood pressure lowering provided greater vascular protection than standard regimens. In high-risk patients, there are additional benefits from more intensive blood pressure lowering, including for those with systolic blood pressure below 140 mmHg. The net absolute benefits of intensive blood pressure lowering in high-risk individuals are large.

Funding

National Health and Medical Research Council of Australia.

By Xinfang Xie (et al), The Lancet , Jan 30, 2016Volume 387Number 10017p403-504

Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2): a randomised, double-blind, crossover trial

Background

Optimal drug treatment for patients with resistant hypertension is undefined. We aimed to test the hypotheses that resistant hypertension is most often caused by excessive sodium retention, and that spironolactone would therefore be superior to non-diuretic add-on drugs at lowering blood pressure.

Methods

In this double-blind, placebo-controlled, crossover trial, we enrolled patients aged 18–79 years with seated clinic systolic blood pressure 140 mm Hg or greater (or ≥135 mm Hg for patients with diabetes) and home systolic blood pressure (18 readings over 4 days) 130 mm Hg or greater, despite treatment for at least 3 months with maximally tolerated doses of three drugs, from 12 secondary and two primary care sites in the UK. Patients rotated, in a preassigned, randomised order, through 12 weeks of once daily treatment with each of spironolactone (25–50 mg), bisoprolol (5–10 mg), doxazosin modified release (4–8 mg), and placebo, in addition to their baseline blood pressure drugs. Random assignment was done via a central computer system. Investigators and patients were masked to the identity of drugs, and to their sequence allocation. The dose was doubled after 6 weeks of each cycle. The hierarchical primary endpoints were the difference in averaged home systolic blood pressure between spironolactone and placebo, followed (if significant) by the difference in home systolic blood pressure between spironolactone and the average of the other two active drugs, followed by the difference in home systolic blood pressure between spironolactone and each of the other two drugs. Analysis was by intention to treat. The trial is registered with EudraCT number 2008-007149-30, andClinicalTrials.gov number, NCT02369081.

Findings

Between May 15, 2009, and July 8, 2014, we screened 436 patients, of whom 335 were randomly assigned. After 21 were excluded, 285 patients received spironolactone, 282 doxazosin, 285 bisoprolol, and 274 placebo; 230 patients completed all treatment cycles. The average reduction in home systolic blood pressure by spironolactone was superior to placebo (–8·70 mm Hg [95% CI −9·72 to −7·69]; p<0·0001), superior to the mean of the other two active treatments (doxazosin and bisoprolol; −4·26 [–5·13 to −3·38]; p<0·0001), and superior when compared with the individual treatments; versus doxazosin (–4·03 [–5·04 to −3·02]; p<0·0001) and versus bisoprolol (–4·48 [–5·50 to −3·46]; p<0·0001). Spironolactone was the most effective blood pressure-lowering treatment, throughout the distribution of baseline plasma renin; but its margin of superiority and likelihood of being the best drug for the individual patient were many-fold greater in the lower than higher ends of the distribution. All treatments were well tolerated. In six of the 285 patients who received spironolactone, serum potassium exceeded 6·0 mmol/L on one occasion.

Interpretation

Spironolactone was the most effective add-on drug for the treatment of resistant hypertension. The superiority of spironolactone supports a primary role of sodium retention in this condition.

Funding

The British Heart Foundation and National Institute for Health Research.

Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2): a randomised, double-blind, crossover trial by Bryan Williams et al.