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16-06-2013 | Cardiology | Article

Mixed success for hypertension treatment algorithm


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medwireNews: An algorithm for treating primary care patients with hypertension and dyslipidemia may help to reduce blood pressure, shows a randomized trial.

However, it did not result in improved control of dyslipidemia, report Ross Feldman (Robarts Research Institute, London, Ontario, Canada) and colleagues.

They believe the mixed success may be partly due to a "ceiling phenomenon" whereby doctors were reluctant to prescribe more than one antihypertensive pill to their patients.

The STITCH2 algorithm may help to address this, however. By the end of the 6-month trial, primary care practices assigned to follow the STITCH2 algorithm had achieved an average 16.2 mmHg reduction in their patients' systolic blood pressure, which was significantly more than the 10.1 mmHg reduction achieved by practices assigned to continue treatment as usual (in line with Canadian guidelines).

The STITCH2 algorithm is a six-step treatment algorithm based on single-pill combination therapy. It begins with a half tablet of a low-dose combination antihypertensive and adds further medications and dose increases until patients' treatment targets are achieved.

There were 35 participating primary care practices, 15 of which were randomly assigned to follow the STITCH2 algorithm, and were educated in the rationale behind the STITCH2 algorithm and given algorithm cards and lists of suitable drug combinations.

During the study period, the number of antihypertensive drugs given to patients in STITCH2 practices increased by an average of 0.79, which was significantly more than the 0.36 increase observed in practices in the control group. STITCH2 practices did not increase dose intensity more than control practices, however.

"The management of hypertension with an algorithm featuring the early use of combination therapy might be seen as means to circumvent the resistance to advancing drug prescription beyond monotherapy," suggest Feldman et al in the Journal of Hypertension.

Also, 73.8% of patients treated in STITCH2 practices received single-pill combination treatments, compared with 26.5% of those treated in control practices, which the researchers say could have contributed to the larger blood pressure reductions in STITCH2 practices.

However, the algorithm had no effect on patients' cholesterol targets. The researchers say this may partly be because therapy started in the second step of the algorithm with a single-pill combination of antihypertensive and antihyperlipidemic therapy, so may have fallen foul of doctors' reluctance to prescribe more than one pill.

They conclude, therefore, that the STITCH2 algorithm was effective for encouraging use of single-pill combination therapy aimed at a single risk factor, but not of crossover pills designed to treat two.

medwireNews ( is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013

By Eleanor McDermid, Senior medwireNews Reporter

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