Patients older than 74 were increasingly less likely to be prescribed a statin for primary prevention of cardiovascular disease, British researchers reported.

But their cross-sectional retrospective study did show that the proportion of people without overt cardiovascular disease who received a prescription for high blood pressure medication rose steadily with age, according to Richard McManus, MBBS, PhD, of the University of Oxford in Oxford, England.

The finding suggests that older people are “largely ignored” by current primary prevention programs in the U.K., which mainly focus on people 74 or younger, the researchers argued online in BMJ.

Cardiovascular disease risk increases with age, they noted, and remains the principal cause of death both in the U.K. and around the world. Nonetheless, British guidelines focus on treating people between 40 and 75, largely because there is little evidence from clinical trials among older people.

To see what effect that has on general practice, McManus and colleagues studied 36,679 patients 40 and older – none of them with a history of cardiovascular disease at the start of the study - from 19 general practices in the West Midlands region of England.

The records included patient demographics, risk factors for cardiovascular disease such as blood pressure and total cholesterol, and prescriptions for primary preventive drugs. For the analysis, patients were subdivided into 5-year age groupings up to 85; those older than 85 were relatively few and were analyzed as a single group.

The researchers analyzed prescribing trends across the study population from Oct. 17, 2008 to Oct. 6, 2009.

They found that the proportion receiving antihypertensive drugs increased with age from 5% of those ages 40 through 44 to 57% of those 85 or older.

Compared with those ages 40 through 44, the odds ratios for being prescribed an antihypertensive drug increased steadily from 1.8 for those ages 45 through 49 to 25.8 for those ages 80 through 85 and then declined slightly to 22.5 for those 85 and older.

In contrast, the proportion of people getting statins rose from 3% for those 40 through 44 to 29% for those ages 70 through 74 and then began to fall with each 5-year increment in age.

Compared with the youngest group, the odds ratios for a statin prescription increased from 1.8 at ages 45 through 49 to 13.6 at 70 through 74, and then fell to 12.9 at 75 through 79, 10.3 at 80 through 84, and to 5.7 for those 85 and older.

There were no consistent differences in prescribing patterns for either type of drug on the basis of sex.

Several studies have suggested that age and sex inequalities exist in secondary prevention of cardiovascular disease, particularly for cholesterol lowering treatment, the researchers noted, and this analysis found some evidence that such disparities also exist in primary prevention.

The findings highlight “the need for a stronger evidence base and clearer guidelines for people aged over 75,” the authors concluded.

They cautioned that, when they estimated the proportion of patients getting therapy, they could not account for contraindications, the doctor’s judgment in individual cases, or patient choice.

They also noted that it was impossible to distinguish between those who were never offered preventive care and those who stopped therapy “perhaps because of side effects or because of increasing age or frailty.”

Primary source: BMJ
Source reference: Sheppard JP, et al “Impact of age and sex on primary preventive treatment for cardiovascular disease in the West Midlands, UK: cross sectional study” BMJ 2012; 345: e4535.

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By Michael Smith, North American Correspondent, MedPage Today