Clinical outcomes meta-analysis: measuring subendocardial perfusion and efficacy of transmyocardial laser revascularization with nuclear imaging

Abstract

IntroductionRandomized and nonrandomized clinical trials have tried to assess whether or not TMR patients experience an increase in myocardial perfusion. However there have been inconsistencies reported in the literature due to the use of different nuclear imaging modalities to test this metric. The primary purpose of this meta-analysis was to determine whether SPECT, MUGA and PET scans demonstrate changes in myocardial perfusion between lased and non-lased subjects and whether laser type affects myocardial perfusion. The secondary purpose was to examine the overall effect of laser therapy on clinical outcomes including survival, hospital re-admission and angina reduction.MethodsSixteen studies were included in the primary endpoint analysis after excluding all other non-imaging TMR papers. Standardized mean difference was used as the effect size for all quantitative outcomes and log odds ratio was used as the effect size for all binary outcomes.ResultsStatistically significant improvements in myocardial perfusion were observed between control and treatment groups in myocardial perfusion at 6-month follow up using PET imaging with a porcine model. However non-significant differences were observed in patients at 3 and 12 months using SPECT, PET or MUGA scans. Both CO2 and Ho:YAG laser systems demonstrated an increase in myocardial perfusion however this effect was not statistically significant. In addition both laser types displayed statistically significant decreases in patient angina at 3, 6 and 12 months but non-significant increases in survival rates and decreases in hospital re-admissions.ConclusionIn order to properly assess myocardial perfusion in TMR subjects, subendocardial perfusion needs to be analyzed via nuclear imaging. PET scans can provide this level of sensitivity and should be utilized in future studies to monitor and detect perfusion changes in lased and non-lased subjects.

VEGF-B Promotes Endocardium-Derived Coronary Vessel Development and Cardiac Regeneration

“…Inspired by studies of blood flow in reptilian hearts and human thebesian veins, attempts to induce endogenous angiogenesis were made previously by introducing tissue channels directly to the myocardium from the ventricles. Such trials failed, however, to demonstrate clear functional benefits or improvement of patient survival 6,7 . The discovery that coronary vessels develop from the sinus venosus 8 , endocardium 9 and, to a minor extent, from the epicardium 10,11 , via vasculogenesis, angiogenesis, and arteriogenesis 8 , has led to the idea that therapeutic reperfusion of the myocardium could be reactivated from these sources in adults.…”

Regenerative concepts in cardiovascular research: novel hybrid therapy for remodeling ischemic cardiomyopathy

“…This angiogenic effect is specific to laser systems that cause tissue injury, with sham-or excimer-lasers causing no vascular response in a swine model (14). In a recent meta-analysis, TMLR was shown to improve myocardial perfusion when assessed by PET imaging (15).…”

Synergistic Effect of Transmyocardial Revascularization and Platelet-Rich Plasma on Improving Cardiac Function After Coronary Artery Bypass Grafting

“…This procedure induces inflammation, endothelialization, and neovascularization in myocardial tissues to renew vascular supply in ischemic areas of the myocardium, thereby improving the function of heart tissue that would not be able to be revascularized with a traditional CABG [8][9][10]. There has been significant evidence in animal models that TMR results in significantly improved myocardial perfusion [11].…”