Are diuretic drugs beneficial in stroke patients?

This article investigated the effect of 2 diuretic drugs called spironolactone and amiloride on myocardial fibrosis and the length of QT segment on ECG in patients with history of a stroke.

The most common cause of death in patients who survived a stroke in recent years is cardiac death rather than recurrent stroke. Previous studies have shown that people who survived a stroke have higher rates of left ventricular hypertrophy or LVH (thickening of the left chamber of the heart muscle). LVH is characterized by the development of myocardial fibrosis or MF (a process in which segments of the heart muscle are replaced by a stiff scar tissue that does not contract properly). Measuring blood levels of a substance called procollagen-1-carboxy terminal peptide or P1CP, is a good predictor of MF.

The function of the heart can be evaluated by a simple electrocardiogram or ECG (electrodes placed on the chest that measure the electrical conductance of the heart). Post-stroke patients often have an abnormality found on the ECG called QT interval prolongation. Diuretic drugs (drugs that tend to increase urine flow to get rid of excess water in the body) such as spironolactone and amiloride, also used to reduce blood pressure levels, increase potassium (a mineral that exists in our body and is crucial for proper heart contraction) blood levels, which is known to reduce the QT interval. MF, as well as prolongation of the QT interval, can increase the risk for life threatening abnormal heart rhythm. This article examined the influence of spironolactone and amiloride on reducing blood levels of P1CP and QT interval prolongation and, therefore, may reduce the risks of cardiac events among stroke survivors.

This study included 11 patients with a history of stroke, prolonged QT interval and various other illnesses such as diabetes, ischemic heart disease (decreased blood supply to the heart muscle) and LVH. The patients were divided into 3 groups, who received either spironolactone, amiloride or a placebo (a substance with no medical effects used as a control when testing new drugs) for 1 month. The patients were followed up by measuring P1CP blood levels and ECG recordings.

Results showed that both spironolactone and amiloride increased potassium levels by an average of 0.42 mmol/L and 0.66 mmol/L, respectively. While spironolactone shortened the QT interval by 18 ms more than the placebo, amiloride shortened the QT time by 25 ms compared to the placebo and also reduced blood pressure levels. Moreover, amiloride showed a greater reduction in P1CP compared to spironolactone.

In summary, this study offered an interesting non-invasive approach for risk assessment in post- stroke patients. It was shown that, in a relatively short period of time, both drugs shortened QT interval and lowered blood levels of P1CP. 

This article included a very small number of participants which may not be statistically significant. This study is the first to show that amiloride can reduce P1CP, though in order to state its actual effect on reduction of cardiac death in stroke patients, further larger trials are needed.

Consult with your physician regarding your heart function and on the most appropriate treatment in your situation.