Barriers that influence secondary prevention
Knowledge about underlying barriers that influence lifestyle behaviour and biological risk factors is a prerequisite for being able to improve secondary prevention (11). The barriers are many and can be categorised as patient-related, treatment-related, healthcare personnel and system-related (11).
The NOR-COR programme studied how clinical, psychosocial, patient-related and treatment-related barriers influence smoking, low-density lipoprotein cholesterol, blood pressure, obesity, physical exercise and diabetes (12). Out of a total of 390 patients who smoked at the time of the index event, 56 % continued smoking (13). Low socioeconomic status, a long history of smoking and non-ST elevation infarction were factors associated with continued smoking in adjusted analyses. The smokers were aware of their risk, and expressed a high level of motivation to quit, but only 42 % reported that they had been offered nicotine replacement therapy or smoking cessation assistance by healthcare personnel. Only 43 % achieved the treatment target for low-density lipoprotein cholesterol of 1.8 mmol/l (14). Ten per cent of patients with unfavourable low-density lipoprotein cholesterol did not use statins at all, while only half were prescribed high-intensity treatment with atorvastatin ≥ 40 mg or rosuvastatin ≥ 20 mg. In patients on low-intensity statin therapy, low self-reported drug adherence and statin-related side effects were associated with 1.6–3.3 times higher probability of missing the low-density lipoprotein cholesterol target in adjusted analyses, while socioeconomic and psychological factors had no impact. Although side effects and low adherence to statins represent a major challenge in clinical practice, a Norwegian study showed that systematic statin treatment run by a cardiologist resulted in 90 % of coronary patients achieving the target for low-density lipoprotein cholesterol (15). The selected patient sample may have influenced the good result, but the findings nevertheless suggest that it is possible to succeed with optimal statin doses in the great majority of coronary patients. The CANTOS study documented for the first time that specific anti-inflammatory treatment of post-infarction patients with high sensitive CRP ≥ 2 mg/l reduces the incidence of cardiovascular events (16). Our study's finding that 46 % of patients with unfavourable low-density lipoprotein cholesterol control had CRP ≥ 2 mg/l was therefore important. Since statins also reduce CRP, this highlights the need to optimise statin treatment before we consider introducing new and often more expensive drugs.
Almost half the NOR-COR patients had poor control of their blood pressure (17). Combination treatments with several classes of antihypertensives are more effective and have fewer side effects than high dosages of single drugs (4). Patients with poor blood pressure control were taking an average of 1.9 blood pressure drugs at the time of their discharge from hospital, while the proportion who took beta blockers or angiotensin inhibitors was significantly lower at the time of the follow-up. Diabetes, increasing age and body mass index were factors associated with poorly controlled blood pressure, while low socioeconomic status, mental stress and self-reported adherence had no impact.