Response to the National Service Framework on coronary heart disease: is it sufficiently evidence-based?

Abstract

Professor Gordon Ferns questions the evidence base for the National Service Framework for Coronary Heart Disease (NSF for CHD). As he pointsout, thedocumentis huge, encompassing12 core standards of care across the primary and secondarypreventionofCHD; themanagementof myocardial infarction,acute coronary syndromes, stableanginaandheart failure;andthe importance of cardiac rehabilitation.For each of these clinical targets is a range of speci®ed milestones to be achieved over the next 5 years, with lists of performance indicators that are to be used to measure success. The document is peppered with speci®c recommendations on interventions, reecting the rich evidence base for the management and prevention of cardiovascular disease. Professor Ferns has identi®ed one speci®c recommendation for which he believes there is insuf®cient evidence to have justi®ed its inclusion. This relates to the milestone that, by April 2002, 80±90% of people discharged from hospital following a heart attack should be prescribed a statin. Professor Ferns is correct in indicating that the evidence for making such a recommendation on ef®cacy ± and indeed safety ± grounds is incomplete. However, as he points out, there are an increasing number of studies formally evaluating this question, namely, how early should secondary prevention with statins be commenced? Indeed, one of the major studies reported at the American Heart Association (AHA) in November 2000 and showed that the early use of statins, within the ®rst 24±48h of presentationwith acute coronary syndromes, is safe, with associated bene®ts in terms of reduced readmission rates. Furthermore, there are data using intermediate outcomes showing that early intervention with statins in acute coronary syndromes improves endothelial function. Data have also shown that the immediate use of a high-dose statin in patients listed for cardiac revascularization will signi®cantly reduce the numbers ultimately receiving such intervention. All of the (admittedly limited) data to date therefore indicate that the practice of early intervention is at least safe ± an important issue highlighted by Professor Ferns. However, I suspect the major rationale for including this recommendation in the NSF does not relate to perceptions that such early intervention will indeed provide incremental bene®t above initiation post discharge. The rationale for starting a statin before discharge relates to data showing that patients are signi®cantly more likely to be taking a statin at follow-up if it is prescribed prior to discharge. In contrast, as we all know, repeated surveys of secondary prevention show signi®cant underperformancein reaching cholesterol targets or initiating statin therapy, even where follow-up is in specialist centres. Therefore, the inclusion of this recommendation is essentially a pragmatic one, to ensure the undoubted bene®ts of secondary prevention by long-term statin use, which are dependent on adequate uptake of treatment. Professor Ferns might argue that there are alternativeways of doing this, such as the greater provision of cardiac rehabilitation to patients (which has secondary prevention therapeutic interventions as an important element) or more effective follow-up arrangements. However, the evidence that these system initiativeswill be more effective than initiating statin use early is lacking. One further point made by Professor Ferns is that the early use of statins may miss secondary hyperlipidaemia or result in unnecessary initiating of treatment. I am not sure why this should be a risk with the use of statins pre discharge. Certainly it will be important for patients admitted to hospital to have their cholesterol measured within the ®rst 24 h of an event, which will avoid the risk of aberrant readings in the immediate post-event period when cholesterol Personal View Ann Clin Biochem 2001; 38: 162±163