Transmyocardial revascularization aggravates myocardial ischemia around the channels in the immediate phase

Overestimation of aortic valve replacement risk by EuroSCORE: implications for percutaneous valve replacement

AIMS

The EuroSCORE has been proposed to identify patients at high risk for surgical aortic valve replacement (AVR) and estimate for them the risk-benefit of percutaneous valve replacement. The aim of our study was to investigate the validity of this proposal.

METHODS AND RESULTS

From 1994 to March 2006, 1545 consecutive patients with aortic stenosis underwent isolated surgical AVR at the Department of Cardiac Surgery of Heidelberg. Both additive and logistic EuroSCOREs were calculated for each patient and summed for expected 30-day mortality. Expected and observed mortalities were compared, particularly with respect to 'high-risk' status and era of operation. Overall, 30-day mortality was low (34/1545, 2.2%) and substantially overestimated by both additive (6.1%) and logistic (9.3%) EuroSCOREs. Although both EuroSCOREs stratified patients monotonically with respect to mortality risk, high-risk patients had a 3.6% mortality (29/833), whereas additive and logistic EuroSCOREs predicted 8.3 and 14.8%. Indeed, none of the 71 patients with a EuroSCORE of 11-20 (extremely high risk) died. The more recent the era of operation, the more pronounced was the discrepancy between expected and observed mortalities.

CONCLUSION

Although the EuroSCORE still successfully stratifies patients undergoing surgical AVR relative to 30-day mortality, it has become increasingly uncalibrated with absolute risk, resulting in overestimation of 30-day mortality. Inaccurately predicted mortality, especially in 'high-risk' patients, renders it unsuitable for assessing risk reduction of percutaneous valve replacement.

Transmyocardial laser revascularization: a review of basic and clinical aspects

Transmyocardial laser revascularization (TMR or TMLR) is a surgical therapy developed to treat patients with debilitating, medically refractory angina pectoris due to epicardial coronary artery disease that is not amenable to treatment using the traditional methods of percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG). This technique can also be applied percutaneously [percutaneous myocardial revascularization (PMR) or direct myocardial revascularization (DMR)]. The original hypotheses which motivated development of TMR were that: (i) oxygenated blood could flow directly from the left ventricle and perfuse the myocardium; and (ii) such artificially created channels would remain patent. However, experimental data have refuted both hypotheses. In the face of early reports of marked clinical benefits in terms of relief of anginal symptoms, alternate hypotheses to explain the mechanism have been pursued, including TMR-associated neoangiogenesis and cardiac denervation. Clinically, numerous reports of reduction in frequency and severity of anginal symptoms, improved exercise tolerance and improved quality of life have appeared from nonblind registry-type studies as well as nonblind randomized clinical trials of TMR or PMR versus continued medical therapy. TMR was not associated with a significant improvement in survival compared with medical therapy alone in randomized trials. For example, the prospective, randomized Angina Treatments-Lasers and Normal Therapies in Comparison (ATLANTIC) trial found a 1-year mortality of 5% in 92 TMR-treated patients and 10% in 90 patients treated with medication only. No proof of improved myocardial blood flow in hearts of treated patients is currently available. The first randomized study of PMR was the Potential Angina Class Improvement From Intramyocardial Channels (PACIFIC) trial which found significantly greater improvements in anginal symptoms and exercise tolerance with PMR plus medical therapy, compared with medical therapy alone. The preliminary results of two double-blind studies with PMR/DMR have been presented but have not yet been published in full. Whereas PMR-treated patients did significantly better than sham-treated control groups after 6 months in the Blinded Evaluation of Laser Intervention Electively For angina pectoris (BELIEF) trial, there was no difference after 1 year between DMR-treated patients and those treated with medication only in the DMR In Regeneration of Endomyocardial Channels Trial (DIRECT). Different devices used for revascularization in these two trials may explain the disparity in the results, and therefore the efficacy and tolerability of each device should be judged upon data collected with that particular device.

[Coronary artery bypass graft combined with transmyocardial laser revascularization. Survival and functional class at one-year follow-up]

INTRODUCTION AND OBJECTIVES

The use of Transmyocardial Laser Revascularization (TMLR) as a strategy to treat unstable angina has been reported in many studies. We analyze its safety and effectiveness in combined procedures (CABG + TMLR).

METHODS

A non-randomized, retrospective cohort study was performed from May 4, 1999 to May 25, 2000 in 21 TMLR patients (18 combined CABG + TMLR) and 118 CABG only procedures. Mortality and NYHA analyses were determined by telephone at follow-up.

RESULTS

Three hospital deaths were observed: one isolated TMLR patient, one valvular + CABG + TMLR patient, and one CABG + TMLR patient. A significantly higher incidence of preoperative angina was found in the group of patients with TMLR + CABG, than in the group with only CABG (83 vs 25%; p < 0.001). There were no differences in age, gender, ejection fraction, Parsonnet and EuroSCORE risk estimation, or mortality (5.1% isolated CABG, 5.6% combined). No episode of angina was detected during follow-up in the CABG + TMLR group: 88% patients were NYHA I, and 21% NYHA II.

CONCLUSION

Incomplete coronary revascularization may be complemented with TMLR in the areas in which CABG is not possible without increased mortality. This technique may avoid postoperative unstable angina due to residual ischemic areas.