Managing Hypertension In Heart Failure Patients In A Teaching Hospital In Ghana

摘要

The study was carried to establish hypertension as the major cause of heart failure in patients seen at the medicine directorate of a teaching hospital in Kumasi. The study also determined the efficiency of the pharmacotherapeutical management of hypertension in these patients. It was retrospective covering a 3-year period i.e. 2004 to 2006. It involved 307 heart failure patients consisting of 54.7% males and 45.3 females aged between 13 to 100 years with the age range of 53-60 years forming the majority. The median age of the patients was 54.6 years with a standard deviation of 18.12. The study was non-randomized and hence all heart failure patients who fell within these periods were used. Hypertension was found to be main cause of heart failure affecting 61.7% (n=189) out of the 307 patients who were admitted for heart failure. The patients had a mean systolic blood pressure of 148.2mmHg (SD.38.49) with the majority (28.7%) having systolic blood pressure in the range of 140-165mmHg. Their mean diastolic blood pressure was 92.60mmHg (SD. 22.32) with the majority (52.4%) having diastolic blood pressure in the range of 90-110mmHg. For asymptomatic heart failure patients with hypertension a thiazide diuretic was found be effective especially for elderly patients over 65 years. 23.8% of the patients in this study received the calcium-channel blocker, nifedipine to treat hypertension in heart failure, however, the newer calcium antagonists, felodipine and amlodipine were more effective in treating arterial hypertension in heart failure. 13.3% of the patients in this study received the β-blocker, carvedilol. Maximizing the dose of β-blockers and ACE-inhibitors, which extend survival in heart failure, was found be more effective than adding calcium-channel blockers to control hypertension. 41.7% of the patients in the study received low dose of the ACE-inhibitor, lisinopril (2.5mg-5mg) to treat symptomatic heart failure due to systolic left ventricular dysfunction, however, maximizing the dosage to 10mg-20mg was found to achieve a decrease in blood pressure as well as improved survival of the patients. The centrally acting drug, methyldopa was administered to 18% of the patients. A dosage of 250-1000 twice daily was found to effectively control their blood pressure. Although most of the patients were discharged with a decreased blood pressure levels the recommended target blood pressure levels of <140/90 or 130/80mmHg could not be achieved. This was due to the fact that most of the patients became asymptomatic and therefore were discharged to be reviewed at the cardiac clinic. Introduction Hypertension has been associated with an increased risk of heart failure in several epidemiological studies. In the Framingham heart study, hypertension was reported as the cause of heart failure either alone or in association with other factors in over 70% of cases, on the basis on non-invasive assessment(1). Hypertension predisposes to the development of heart failure via a number of pathological mechanisms, including left ventricular hypertrophy. Left ventricular hypertrophy is associated with left ventricular systolic and diastolic dysfunction and an increased risk of myocardial infarction and it predisposes to both atrial and ventricular arrhythmias. Electrocardiographic left ventricular hypertrophy is strongly correlated with the development of heart failure, as it is associated with a 14-fold increase in the risk of heart failure in those aged 65 years or under(16). There have been worrying reports recently both in epidemiology and clinical outcomes of hypertension in recent studies. Hypertension has been reported to account for up to 30% of hospital admissions for heart failure in West Africa(3) and the prognosis of hypertensive heart failure among black Africans has also been found to be poor(4). Amoah and Kallen found the main cause of heart failure in Accra, Ghana to be hypertension(5). Owusu, I., in Kumasi also found the main cause of