Risk factors for myocardial ischemia in patients with resistant hypertension

The aim of this study was to identify risk factors for myocardial ischemia (reduced blood flow to the heart) in patients with resistant hypertension. The authors identified a number of risk factors that increase the likelihood of myocardial ischemia in patients with resistant hypertension.

Patients with hypertension have a higher resting blood pressure than the body needs. The blood pressure needs to be lowered to avoid cardiovascular complications such as heart attacks, strokes and heart failure. Resistant hypertension, where blood pressure is consistently higher than 140/90 mm Hg, usually requires treatment with three or more drugs.

Resistant hypertension can lead to serious conditions. These include endothelial dysfunction (lining of the blood vessels not controlling blood flow correctly), microalbuminuria (kidneys leaking unwanted proteins into the urine) and increased thickness of the left heart cavity. All of these can lead to myocardial ischemia, a type of heart attack where the blood flow to the heart is reduced. Identifying risk factors of myocardial ischemia is important for appropriate management of resistant hypertension early on.

129 patients with resistant hypertension were included in this study. 28% of these patients had myocardial ischemia. General health and measures of hearth health were compared across patients with myocardial ischemia and those without.

The rate of diabetes was 6.5 times higher in the group that was positive for myocardial ischemia. Patients with myocardial ischemia were also more often categorized as obese (75%) compared to those without myocardial ischemia (40%).

On average, endothelial function was 78% lower and heart rate 23% higher if myocardial ischemia was present. Poor kidney function and increased thickness in the lining of the heart were also more commonly seen in patients with myocardial ischemia.

This study concluded that increased heart rate, thickness of the left heart cavity, diabetes, endothelial dysfunction, and poor kidney function can each significantly increase the risk of myocardial ischemia in patients with resistant hypertension.

Larger studies are needed to confirm these results.