Percutaneous Transmyocardial Laser Revascularization for Severe Angina: The PACIFIC Randomized Trial - PACIFIC

Description:

Percutaneous Transmyocardial Laser Revascularization for Severe Angina: The PACIFIC Randomized Trial.

Hypothesis:

To determine the safety and efficacy of percutaneous transmyocardial revascularization (PTMR) in patients with limiting angina when bypass or angioplasty is not an option.

Study Design

Study Design:

Patients Enrolled: 221

Primary Endpoints:

An increase in exercise duration at 12 months compared with baseline.

Secondary Endpoints:

A 12-month survival, angina scores and Seattle angina questionnaire index.

Drug/Procedures Used:

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.

Principal Findings:

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 non-significant 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.

When compared with medical therapy alone, PTMR results in increased exercise tolerance, lower angina scores and improved quality of life.

Interpretation:

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.

References:

1. Oesterle SN, Sanborn TA, Ali N, et al. Lancet 2000;356:1705-10.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Pericardial Disease, Atherosclerotic Disease (CAD/PAD), Implantable Devices, SCD/Ventricular Arrhythmias, Aortic Surgery, Cardiac Surgery and Arrhythmias, Interventions and Coronary Artery Disease

Keywords: Exercise Tolerance, Coronary Artery Disease, Follow-Up Studies, Transmyocardial Laser Revascularization, Angioplasty, Pericardiocentesis, Tachycardia, Ventricular, Quality of Life, Placebo Effect, Myocardial Revascularization, Thallium, Maximum Tolerated Dose, Questionnaires, Bradycardia, Exercise Test


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