17 March 2021

Middle-aged hypertensive patients poorly controlled

Cardio Clinical

Only two out of five middle-aged adults treated for hypertension are meeting blood pressure targets in the UK, according to one of the largest population-based studies of its kind.

Patients with hypertension risk factors – including older age (60–69 years), male sex, Black ethnicity, and consumption of over 30 units of alcohol per week – were less likely to have their hypertension controlled, as were those who appeared to have a lower socioeconomic status.

However, people with comorbidities tended to have better controlled hypertension – even if the comorbidity was unrelated to cardiovascular disease.

The Oxford University-led team suggested this might be explained by more frequent contact with health professionals, medication adherence counselling from healthcare providers, and more opportunistic screening.

Those with CVD-related risks may be managed more aggressively, they added.

“This hypothesis is supported by our finding that smokers and those have migraines are more likely to be controlled, and that a higher percentage of participants with CVD risk factors were on three or more antihypertensives,” the authors wrote in BMJ Open Heart.

The team warned that despite only 38% of almost 10,000 study participants having controlled their hypertension, rates may be even lower in the real world.

For the new study, the researchers drew on the UK Biobank (UKB), a population-based prospective cohort study involving 500,000 adults living near centres across England, Scotland and Wales between 2006 and 2010.

They selected people from the UKB aged 40–69 years with a prior diagnosis of hypertension and who were already using antihypertensives.

But it’s been shown that UKB participants differ from nationally representative surveys in the UK – for example they were more likely to be educated and less likely to be obese, the authors said.

“Participation in the UKB was by volunteers for a longitudinal study and required visiting study assessment centres.

“Our estimated prevalence of hypertension control may thus not accurately reflect prevalence in the UK’s general population aged 40 to 69 years, and might be anticipated to overestimate this prevalence.”

However, cardiovascular disease expert Professor Mark Nelson told TMR that the general findings of the study are in line with existing research, and likely apply to Australia’s population. GPs can help address the issues such as the poorer control among patients with CVD risk factors, he said.

“It is complicated but addressable. For example, … [an] effective strategy is low dose combination medications which are cost-effective and efficacious,” said Professor Nelson, a GP and the medical director of the Blood Pressure Clinic at the Menzies Institute for Medical Research at the University of Tasmania.

Professor Nelson agreed with the authors’ suggestion that patients with comorbidities may be better controlled because they interact with the healthcare system more often.

“The concept of absolute risk approach to blood pressure management is still not widely practiced though it is a superior approach,” Professor Nelson said.

“[However, this study] deals with ‘hypertension’ rather than blood pressure control, i.e., the old concept of all over SBP 140 should be treated to 139 rather than high risk individuals should have their BP reduced irrespective of the level and based on tolerability,” he said.

The authors’ definition of hypertension control was a mean systolic blood pressure <140 mmHg and diastolic blood pressure <90 mmHg. This was consistent with clinical guidelines at the time of recruitment, but studies have since shown the benefit of a systolic blood pressure target of <120 mmHg.

BMJ Open Heart 2021, 11 March

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