[The European Society of Cardiology (ESC) guidelines for percutaneous coronary interventions (PCI). Three case reports].

The European Society of Cardiology (ESC) for the first time issued guidelines for percutaneous coronary interventions (PCI) in spring 2005. The strengths of recommendations stated in the ESC guidelines (as in those of the AHA/ACC [American Heart Association/American College of Cardiology]) are traditionally a combination of recommendation classes (I, IIa, and IIb) and a level of evidence (A, B, or C). This paper explains and discusses selected focal points of the ESC PCI guidelines based on three representative cases from daily practice. 1. Stable coronary artery disease (CAD): PCI in a 53-year-old patient without angina pectoris and proof of myocardial ischemia. With a clear indication of ischemia in the anterior myocardial wall, the ESC PCI guidelines indicated coronary angiography with possible PCI, even without angina pectoris symptoms. Cardiac catheterization showed a 99% proximal LAD stenosis, which was immediately dilated and stented based on the indicated ischemia. According to the ESC PCI guidelines, an intervention is indicated for CAD when a larger ischemic area is clearly evident even in the absence of typical angina (recommendation class I A). 2. ST segment elevation myocardial infarction (STEMI): PCI even after successful thrombolysis. A 70-year-old patient experienced acute substernal pain and immediately went to his nearby hospital. The ECG clearly showed anterior myocardial wall STEMI, which in this hospital without a cardiac cath lab indicated thrombolysis, since it could be initiated within 3 h after the onset of chest pain. Pain relief was evident soon after thrombolysis, combined with a resolution of the ST segment elevations. As suggested by the ESC PCI guidelines, a transfer to a cardiac cath lab took place the next day, where the 50% residual stenosis of the LAD was stented. The ESC PCI guidelines suggest coronary angiography with possible PCI within 1-2 days following successful thrombolysis (recommendation class I A). Thus, even "successful" thrombolysis is not regarded as the final treatment for STEMI. 3. Premature termination of clopidogrel after stent implantation: stent thrombosis with acute myocardial infarction. A 46-year-old patient visited the practice due to increasing dyspnea. 4 months earlier, a Taxus stent had been implanted at a heart center into the second RPLS of the RCX; 3 days later, a Cypher stent was implanted in the LAD. Upon being discharged on a Friday at noon, the patient was advised to see his general practitioner soon to attain a prescription for clopidogrel. The patient was given an appointment at his general practitioner for the following Wednesday afternoon. But on that Wednesday morning the patient went into cardiogenic shock. Although the occluded LAD (stent thrombosis) could be quickly reopened, left ventricular myocardium became severely damaged. Until a cardiac transplantation will be performed, a defibrillator was implanted. This "organizational" gap in clopidogrel administration did not conform to the ESC PCI guidelines: after implantation of any coronary stent, dual antiplatelet treatment (acetylsalicylic acid and clopidogrel) must be consistently administered for at least 4 weeks. After implantation of drug-eluting stents (DES), the ESC PCI guidelines call for clopidogrel administration for at least 6 months; when small vessels, long lesions or a complex anatomy (e. g., bifurcation stenting) are involved, a duration of 1 year or even longer is recommended. The optimal duration of platelet aggregation inhibition following PCI with DES of unprotected left main stem stenoses is unknown at this time. The traditional levels of evidence according to ESC, AHA and ACC criteria (levels A, B, or C) do no longer meet the actual requirements to assess the scientific evidence of randomized PCI trials and registry studies. For example, only two small randomized studies with few patients and insufficient statistical power utilizing a clinically insignificant surrogate endpoint would be enough to attain level of evidence A. Consequently, a new scoring system will be proposed, which considers criteria such as the importance of a primary clinical endpoint, the statistical power achieved, and the presence of an independent external data review and safety monitoring board.