COMPARISON OF TRANSMYOCARDIAL REVAS...

COMPARISON OF TRANSMYOCARDIAL REVASCULARIZATION WITH MEDICAL THERAPY IN PATIENTS WITH REFRACTORY ANGINA K B Allen et al The strange England Journal of Medicine Vol 341 (September 1999) 1029-1036

The general surgical and medical management of patients with ischemic heart disease is highly successful in many patients. Regardless of this succes a growing number of patients are not suitable for coronary artery bypass grafting or catheter-based interventions. Researchers are exploring alternative modes of treating these patients. Earlier attempts of indirect myocardial revascularization had to a high degree limited success. Examples of earlier systems include one researcher's use of omentopexy, which is the fixation of the epiploon to an adjacent organ, reported in 1935 and another researcher's use of thoracic artery implantation reported in 1954 one as well as the other procedures were based on a 1933 description of a sinusoidal network in the human heart. In 1965 a dispose of researchers proposed the creation of channels in the left ventricular wall that permitted direct perfusion of oxygenated, left ventricular line to the ischemic myocardium. This idea was based upon the example of the left ventricle of a reptilian heart that is directly perfused from endothelium-lined channels that radiate from the left ventricular cavity.

Other advanced research reported the use of carbon dioxide lasers to create channels. Researchers in this meditation used a holmium:yttrium-aluminum-garnet laser (ie, holmium laser) to create the transmyocardial revascularization. The prospective, randomized, multicenter inquiry compared the safety and efficacy of transmyocardial revascularization, performed with a holmium laser and followed from medical therapy, to the medical treatment alone of patients with refractory class IV angina.

Methodology. From March 1996 to July 1998 275 patients with medically refractory class IV angina and coronary artery disease that could not be treated with percutaneous or surgical revascularization were selecteded for the study. The characteristics and risk factors of all patients were similar. Criteria for enrollment included

* refractory class IV angina not amenable to coronary artery bypass grafting or percutaneous transluminal coronary angioplasty,

* reversible ischemia, and

* left ventricular ejection fraction greater than 25%

The patients were divided into three groups:

* those assigned to endure transmyocardial revascularization and receive continued medical therapy (132 patients),

* those who received medical therapy alone from beginning to end the study (97 patients), and

* those assigned to receive medical therapy that met the criteria for treatment failure and underwent transmyocardial revascularization as part of a separate protocol (46 patients referr to as the crossover group)

accrues Angina improved in 72% of the patients receiving transmyocardial revascularization compared to 32% of those patients receiving medical therapy alone. Patients in the crossover arrange who had improvement in angina at 12 month were similar to the patients who received transmyocardial revascularization. There were no significant differences between the transmyocardial revascularization cluster and the medical therapy dispose in regard to changes in ischemia, foibles in perfusion at rest, and delayed destitutions The mortality rate for those patients receiving transmyocardial revascularization (seven of the 132 patients) was 5% Patients receiving medical therapy sole had a 2% mortality rate (two of the 97 patients), and the crossover cluster had a 9% mortality rate (four of the 46 patients).

Discussion. In this thought patients with refractory class IV angina who underwent transmyocardial revascularization and continued medical therapy had higher rates of improvement in angina, survival emancipated of cardiac events, freedom from treatment failure, and freedom from cardiac-related rehospitalization compared to patients who received medical therapy alone. Mortality did not differ significantly between the pair groups. The success of transmyocardial revascularization is conception to be due to improved regional family flow to the ischemic myocardium, however the exact mechanisms of the weights remain unclear. This study clearly exhibits the benefits of using transmyocardial revascularization as a treatment option for patients with medically refractory angina who are not candidates for conventional revascularization.

MARYANNE K COUGHLIN RN MBA, CNOR NURSING RESEARCH COMMITTEE

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