Multivessel percutaneous coronary intervention: a new paradigm for a new century.
Percutaneous coronary intervention (PCI) was introduced in 1977, to treat single, discrete lesions in patients with stable symptoms, and favorable anatomy. Increased operator experience and numerous technical advances, notably including bare-metal stents (BMS) and then drug-eluting stents (DES), and a number of adjunctive pharmacologic modalities, have allowed for the gradual application of PCI to far more diverse clinical and anatomic subsets. The proper role of PCI, compared with both medical therapy and coronary artery bypass graft (CABG) surgery, is evolving. This manuscript is synthesized from literature review of randomized clinical trials, and some cohort investigations, and 21 years of PCI experience, which has been focused on high-risk patients. Current American College of Cardiology/ American Heart Association/ Society for Cardiac Angiography and Interven-tions (ACC/AHA/ SCA&I) Guidelines, and most research, are based upon a perspective (conventional paradigm') that categorizes patients primarily based upon number of major' coronary (left anterior descending artery, circumflex and right) arteries with a >70% stenosis, and whether left ventricular function is normal or abnormal (left ventricular ejection fraction < or >0.50). This paradigm developed when: a) CABG was the only revascularization option, and b) medical therapy was quite limited. All of the trials demonstrating survival benefit with aspirin, clopidogrel, statins, angiotensin-converting-enzyme inhibition (ACE-I) or angiotensin receptor blockers (ARB), and beta-blockers; coupled with the PCI versus thrombolytics trials in ST-elevation myocardial infarction (STEMI), and non-STEMI strategy trials, both of which include revascularization almost exclusively by PCI, make this conventional paradigm, outdated and counterproductive. Attempts to compare CABG and PCI have de-emphasized their very different advantages and disadvantages. The new paradigm makes major division of patients based upon whether patients have stable or unstable: a) ischemia and b) hemodynamics, and c) whether they are having acute myocardial infarction (MI). The first issue to be settled is whether the patient is likely to benefit from revascularization. If little or no benefit can be envisioned, the patient should be managed medically. Unstable ischemia and unstable hemodynamics, and acute MI, all favor emergent or urgent revascularization. Clinical features, which generally favor PCI for revascularization, include hemodynamic instability, STEMI and non-STEMI; and severe comorbidity, particularly cerebral, pulmonary, or hepatic comorbidity. Anatomic features, which generally favor CABG, include unprotected left main stenosis, especially involving the bifurcation, one or more graftable chronic total occlusions (CTO), and bifurcation disease with large important side-branches. Old age and severely reduced left ventricular function are associated with higher risks, with either CABG or PCI. Small caliber and diffusely diseased vessels may imply lower expectation of success, by either CABG or PCI.
Morrison
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Cardiology Section 111-C, Southern Arizona Veterans Affairs, Healthcare System, Tucson, AZ 85723, USA. douglass.morrison@med.va.gov
D015906:Angioplasty, Balloon, Coronary / Q000379:methods* / Q000639:trends; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000628:therapy*; D005544:Forecasting; D006801:Humans; D015607:Stents