Risk factors

The top-ranking risk factors for CHD are nicotine abuse (even passive smoking increases the risk by about 25%), high blood pressure (hypertension), diabetes mellitus, disorders of lipid metabolism (hypercholesterolaemia: total cholesterol > 250 mg/dl, LDL > 160 mg/dl, HDL < 35 mg/dl, hyperlipidaemia) and a familial/genetic disposition (myocardial infarction in siblings or parents). 

Lower-ranking risk factors are overweight (obesity, > 30% above desirable weight), raised lipoprotein A levels (Lp(A) >30 mg/dl), fibrinogen levels and homocysteine levels (> 9 mmol/l) along with lack of exercise and emotional stress.

 

 

 

Complications of CHD and myocardial infarction

The early complication, i.e. in the first 48 hours, is electrical instability of the heart with arrhythmias especially ventricular fibrillation, which occurs in 80 % of the patients who die of “cardiac arrest“ during infarction, especially in the first few hours after the onset of infarction. When dangerous ventricular arrhythmias persist, cardiac surgeons and cardiologists can implant a cardioverter defibrillator (AICD or “Defib“), usually also with pacemaker function.

If there is marked left heart insufficiency with imminent heart failure resulting in pulmonary congestion and pulmonary oedema and with the onset of cardiogenic shock (10 - 15% of cases (ventricular fibrillation and pump failure are the two most frequent causes of death after infarction), cardiac surgeons can implant an intra-aortic balloon pump (IABP) or a mechanical circulatory support system (assist device) as a final life-saving measure as an emergency procedure.

Later complications of an extensive myocardial infarction can be rupture of the cardiac muscle wall with haematoma in the pericardium (pericardial tamponade), which has to be treated by emergency cardiac surgery. A tear of the ventricular septum (detectable on echocardiography) and necrosis of parts of the mitral valve (papillary muscle necrosis or tear with acute high-grade mitral insufficiency, which can be relieved only by immediate valve replacement) are late complications. Even after 6 weeks, a cardiac wall aneurysm (ballooning of the scar) can occur in 10% of all infarction patients. The complications of an aneurysm are the risk of embolism resulting in a stroke, left heart failure, arrhythmias and rupture of the aneurysm with pericardial tamponade. The cardiac wall aneurysm is therefore resected surgically here. Generally, the lifetime probability of developing CHD is nearly 50% for men and 32% for women.