Cape Town -
A significant number of heart disease patients in Cape Town, previously hospitalised for the life-threatening disease, are putting themselves at risk of heart attacks and death by continuing to smoke and not taking their preventative medication, a UCT study has found.
The study, published in the latest issue of SA Medical Journal, analysed the use of maintenance drugs, such as aspirin, statins, beta-blockers and Angiotensin-converting enzyme (ACE) inhibitors.
Among 164 ischemic heart disease patients discharged from Groote Schuur Hospital’s coronary care unit between November 2011 and April 2012, researchers found a default rate of 23.5 percent between six and nine months after discharge and only 31 percent of smokers had quit.
Aspirin, which helps prevent heart attacks in people with ischemic heart disease, had been stopped by 9 percent of patients, while statins, which are used to lower cholesterol, had been discontinued by 10 percent of them.
Beta-blockers, commonly used for controlling high blood pressure and improving blood flow to the heart, recorded a 6 percent default rate while Ace inhibitors, which are used to lower blood pressure, were discontinued by 18 percent of patients.
Ischaemic heart disease (IHD) is a major cause of mortality in the Western Cape. In 2000, the South African national burden of disease study described it as the largest single cause of death in the province at 12 percent, followed by stroke at 8.8 percent and HIV/Aids at 8.4 percent.
The use of medical therapy such as aspirin and statins after acute coronary syndrome is known to reduce mortality by up to 87 percent in the first six months following a heart attack.
Of the 164 patients who formed part of the study group, 19, or 11.6 percent, had died while another 11.6 percent of patients could not be contacted.
About 95 percent were discharged on aspirin, on follow-up at six months only 85 were still on it, with most defaulters saying they did not realise its importance. Some said they had been put on alternative therapy while others cited anaemia as a side-effect of the drug. Most of those who defaulted on statins cited nausea and not knowing its importance as the main reasons for discontinuing with treatment, while those who defaulted on beta-blockers either pleaded ignorance of its importance or reduced heart rate.
Ace inhibitors, which recorded the biggest default rate, were dropped because patients either experienced coughing, or their doctor stopped it because of low blood pressure; others were ignorant of its significance.
Of the 79 smokers (56 percent of the total patients) registered during admission into hospital, only 22, or 31.4 percent, had quit at six months follow-up. One patient took up smoking for the first time after discharge.
Researchers were concerned about the findings, arguing that even though there was good early initiation of these prevention drugs, adherence was disappointingly low.
Lead researcher Bradley Griffiths wrote: “What is more concerning is that patients stopped medication because they did not realise the importance of ongoing use, which was found to be a reason for non-adherence.”
The study found no link to language or income, citing that it was possible that level of education and insight into disease could have played a role in the default rate.