Ann Thorac Surg 2003;75:1412-1413
© 2003 The Society of Thoracic Surgeons
Original article: cardiovascular
Invited commentary
James R. Pluth, MDa
a Mayo Clinic13,400 East Shea BlvdScottsdale, AZ 85255, USA
(Email: jrpluth{at}aol.com).
For the past 30 years, the use of arterial and venous conduits have provided not only symptomatic relief but have prolonged the life of millions of patients with atherosclerotic heart disease. In some instances, less than ideal results were achieved due in large part to poor distal runoff and small target vessels, but in general, these were considered the breaks of the game. In their paper, Kleikamp and colleagues present their long-term results on surgical revascularization on a select group of patients, namely those with ischemic cardiomyopathy. The surprising conclusion that the authors make is that poor coronary vessels represent an independent variable for patient selection and that patients with poor coronary vasculature, regardless of myocardial viability, should not be considered suitable for revascularization.
The authors state that the incidence of angina in patients operated upon decreased from 94% to 34% during the years of the study. This alone is worthy of further evaluation. Collateral circulation was noted in over half of the entire cohort, and one must assume that it must have been adequate to provide sufficient perfusion to prevent ischemic symptoms. A corollary to this is that, although contractility may be impaired, sufficient blood supply must have been present to preserve myocardial viability. (Were these collaterals the result of the multiple nonsurgical interventions in these patients prior to surgery?) It is rare for atherosclerotic disease to progress in vessels whose only blood supply is derived from collateral circulation. Therefore, the two factors of good distal vessels and myocardial viability are probably not independent variables, but related. It would be of interest to note whether improvement in surgical results were related to the decrease in angina in the later years of the study and whether the small difference in "P" values between poor distal vessels and myocardial viability were an aberrancy of the early years of the study.
Denying the patient surgical revascularization only on the basis of the quality of the distal vessel is somewhat ethically troubling. The average age of patients was 60 years, and half of them had hypertension or elevated cholesterol. One-third had peripheral vascular disease, carotid disease, diabetes, or renal failure. Few would ever rise to the top of a transplant list even if availability of donor hearts was adequate. It is true that half of the patients appeared to have had adverse results by 16 months postoperatively, but the converse is also true that 50% lived beyond that point and 20% lived 5 or more years before having an adverse event. Unfortunately, the quality of life in patients after surgery with poor distal vessels was not provided in this paper. The average ejection fraction did not change suggesting that there was no improvement, but what alternative do we have for these patients? Ventricular assist devices are certainly not free of adverse events. Here, one must question whether a variation of surgical technique might have improved the surgical outlook for some of these patients. The authors employed intermittent ischemic arrest with mild hypothermia. Mean ischemic time was but 25 minutes (range, 0–46), but the method of protection would not seem to be adequate to provide time for extensive endarterectomy, multiple skip grafts, or long on-lay arterial grafts that might provide better distal flow and be reflected in improved outcome.
Irrespective of the above concerns, one must keep in mind that the conclusions provided from these authors with their extensive experience and excellent surgical results in this difficult group of patients must be considered as one approaches the patient with ischemic cardiomyopathy.
