Cardiovascular complications in the diabetic patient with renal disease: an update in 2003.

Coronary heart disease [defined as myocardial infarction, angina, history of bypass surgery, percutaneous transluminal coronary angiography (PTCA) or pathology on coronary angiography] is frequently found in patients starting dialysis. Stack and Bloembergen [1] examined a national random sample of 4025 patients entering renal replacement programmes in the USA. The prevalence of coronary heart disease was 38% and it was significantly more common in diabetic patients (46.4%) than in nondiabetic patients (32.2%). This difference was highly significant on multivariate analysis. Much of the cardiac pathology is acquired prior to dialysis. This is documented by the high frequency of coronary lesions, i.e. 30–40%, which is found when diabetic patients undergo coronarography before they are put on the waiting list for transplantation. The conclusion that much of the cardiac pathology is acquired even before the pre-terminal phase of renal disease is supported by the Canadian multicentre observation cohort where the prevalence of cardiovascular disease was 47%, independent of the severity of renal dysfunction. Progression, i.e. either new events or worsening of existing pathology, was seen in 20% of the patients over 23 months [2]. The odds ratio for a new event in diabetic compared with nondiabetic patients was 5.3 and this difference was highly significant. An increased risk of cardiac complications was noted in patients, including diabetic patients, who had only mild to moderate renal failure and had developed myocardial infarction. Acute and postdischarge mortality was significantly elevated [3,4] and the renal patients had more frequent atrial and ventricular arrhythmia, heart block, asystole, pulmonary congestion and cardiogenic shock [5]. This adverse outcome was only in part explained by the less frequent use of thrombolysis, active intervention and cardioprotective medication. Once the diabetic patient is on dialysis the prevalence of cardiac morbidity and the risk to develop ischaemic heart disease de novo is high, as documented by several studies. The most impressive information is provided by an inception cohort of 433 Canadian patients, 116 of whom were diabetics [5,6]. At baseline (Table 1), diabetics had more left ventricular hypertrophy (LVH), more ischaemic heart disease and more congestive heart failure. No difference between diabetic and nondiabetic patients was found with respect to the de novo appearance or progression of LVH and congestive heart failure. In contrast, the relative risks of de novo ischaemic heart disease as well as overall and cardiovascular mortality were significantly higher in the diabetic patients. This observation is consistent