One-Year Survival Following Early Revascularization for Cardiogenic Shock
Methods: A total of 221 patients were randomized to either PTMR plus medical treatment (110 patients) or to medical treatment alone (111 patients). Eligible patients had to have Canadian angina class III or IV despite maximal tolerated doses of at least 2 antianginal drugs, ejection fraction ⬎30%, reversible ischemia on thallium stress test and were not candidates for bypass surgery or angioplasty. The primary end point was increase in exercise duration at 12 months compared with baseline. Secondary end points included 12-month survival, angina scores and Seattle angina questionnaire index. Results: Ten patients in the PTMR group underwent PTCA during the follow-up time, and 14 patients in the medical therapy group had other interventions (11 PTCA, 2 CABG and 1 TMR). Complications of PTMR included bradycardia (3 episodes, 1 necessitating a permanent pacemaker), ventricular tachycardia (1 episode), myocardial perforation (3 episodes, 1 requiring pericardiocentesis), CVA (2 episodes), TIA (1 episode) and vascular access complications (2 episodes). At 12 months follow-up, there was a nonsignificant trend toward a higher mortality rate in the PTMR group (8 death in the PTMR group and 3 death in the medical group, p ⫽ 0.12). The median increase in exercise duration was significantly higher in the PTMR group when compared with the medical therapy group (89 s vs. 12.5 s, p ⫽ 0.008). A ⬎60 s increase of exercise duration was observed in 54% of PTMR patients and 39% of medical therapy patients (p ⫽ 0.06), while on masked assessment, angina class was II or lower respectively in 34.1% and 13.0% of treated patients. All indices of the Seattle angina questionnaire increased more in the PTMR group than in the medical therapy group. An investigator bias in favor of PTMR was detected when comparing investigator assessment and masked assessment of angina. Conclusion: When compared with medical therapy alone, PTMR results in increased exercise tolerance, lower angina scores and improved quality of life. Perspective: This study highlights some of the difficulties in conducting clinical trials comparing interventional treatments with medical treatment in patients with end stage coronary artery disease. There was no attempt to blind the patient or the investigator to treatment assignment, and 10% of patients underwent treatments that were considered exclusion criteria. Therefore, despite the randomized study design, it is not possible to exclude that the beneficial effect of PTMR on exercise duration, angina scores and quality of life is due at least in part to a placebo effect. MM
Hochman JS, Sleeper LA, White HD, et al. JAMA 2001; 285:190 –2. Study Question: To determine the effect of early revascularization on 1-year survival for patients presenting with cardiogenic shock (CS). Methods: The study population included 352 patients with CS enrolled in the SHOCK trial. Of these, 152 patients were randomized to early revascularization (ERV) within 6 hours of randomization including angioplasty (55%) and coronary artery bypass graft surgery (CABG) (38%), and 150 patients were randomized to initial medical stabilization (IMS) including intra-aortic balloon counterpulsation (86%), thrombolysis (66%) and subsequent revascularization with PTCA or CABG permitted 54 hours or more after randomization (25%). Results: The 1-year survival was significantly higher in patients randomized to ERV when compared with patients randomized to IMS (46.7% vs. 33.6%, p⬍ 0.03, RR for death, 0.72; 95% C.I., 0.54 – 0.95). A subgroup analysis revealed a significant treatment interaction with age (p ⫽ 0.03, age ⬍75 vs. age ⱖ75 years). There was a significant survival benefit with ERV for patients ⬍75 years old (1-year survival of 51.6% for ERV vs. 33.3% for IMS) and no significant benefit for patients ⱖ75 years old (1-year survival of 20.8% for ERV vs. 34.4% for IMS). There was no interaction with gender, randomization 6 hours or less after MI, anterior MI, diabetes mellitus, hypertension, US site, transfer and thrombolytic contraindication. At 1-year, 85% of patients in the ERV group and 80% of patients in the IMS group were NIHA congestive heart failure class I or II. Conclusions: ERV results in a significant survival benefit at 1-year for patients presenting with acute MI complicated by CS. Perspective: The SHOCK randomized trial can be considered a milestone in the treatment of patients with acute myocardial infarction complicated by CS. It confirms the survival benefit of ERV that had been in the past observed in registry studies, and it supports a strategy of ERV or of rapid transfer for ERV for patients with CS. The lack of benefit and possibly worse outcome observed in older patients suggest that a routine strategy of ERV should not be applied to this patient subgroup. However, a survival benefit was observed for elderly patients with ERV in the SHOCK registry. Thus, as the authors conclude, it is possible that careful case selection could result in improved outcomes also in this patient population. MM
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