Additional improvement in regional myocardial ischemia after intracardiac injection of bone marrow cells during CABG surgery

Background

Post-procedure residual ischemia is associated with worse prognosis in patients with coronary artery diasease (CAD).

Objective

We evaluated whether autologous bone marrow-derived cells (BMC) contribute to additional reduction in regional stress-induced myocardial ischemia (SIMI) in patients undergoing incomplete coronary artery bypass graft surgery (CABG).

Methods

In a double-blind, randomized, placebo-controlled trial, we enrolled 143 patients (82% men, 58 ± 11 years) with stable CAD and not candidates for complete CABG. They received 100 million BMC (n = 77) or placebo (n = 66) injected into ischemic non-revascularized segments during CABG. The primary outcome was improvement on SIMI quantified as the area at risk in injected segments assessed by cardiovascular magnetic resonance (CMR) 1, 6, and 12 months after CABG.

Results

The reduction in global SIMI after CABG was comparable (p = 0.491) in both groups indicating sustained beneficial effects of the surgical procedure over 12 month period. In contrast, we observed additional improvement in regional SIMI in BMC treated group (p = 0.047). Baseline regional SIMI values were comparable [18.5 (16.2-21.0) vs. 18.5 (16.5-20.7)] and reached the lowest values at 1 month [9.74 (8.25; 11.49) vs. 12.69 (10.84; 14.85)] for BMC and placebo groups, respectively. The ischemia's improvement from baseline represented a 50% difference in regional SIMI in favor of the BMC transplanted group at 30 days. We found no differences in clinical and LVEF% between groups during the 12 month follow-up period. The 1 month rate of major adverse cerebral and cardiovascular events (MACCE) (p = 0.34) and all-cause mortality (p = 0.08) did not differ between groups 1 month post intervention.

Conclusion

We provided evidence that BMC leads to additional reduction in regional SIMI in chronic ischemic patients when injected in segments not subjected to direct surgical revascularization. This adjuvant therapy deserves further assessment in patients with advanced CAD especially in those with microcirculation dysfunction.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT01727063.

High Mortality Associated With Precluded Coronary Artery Bypass Surgery Caused by Severe Distal Coronary Artery Disease

Background— Patients with extensive coronary artery disease (CAD) have better prognosis when treated with coronary artery bypass grafting surgery (CABG), especially when left ventricular dysfunction (LVD) is present. However, there are scanty data about the clinical course of patients not referred to CABG because of extensive and severe atherosclerotic involvement of distal coronary arteries (ENDCAD). The aim of this study was to evaluate patients with multivessel (MV) or left main CAD (LM) who had CABG precluded because of ENDCAD.

Methods and Results— Between August 1999 and July 2001, 51 patients who had clinical indication but were not eligible for CABG because of ENDCAD were followed for at least 12 months or until death. There were 32 men and 19 women (age 61±9 years). Previous acute myocardial infarction (AMI) was present in 31 (60.8%), diabetes mellitus (DM) in 28 (54.9%), systemic arterial hypertension in 37 (72.5%), LVD (left ventricular ejection fraction <40%) in 26 (51%), 3 vessel CAD in 31 (60.8%), and LM in 4 (7.8%). During follow-up there were 20 cardiac (39.2%) deaths, 19 (37.2%) AMI, and 3 (5.8%) patients developed congestive heart failure. There were 2 (3.9%) noncardiac deaths. Patients with DM (60.7% versus 13%; P =0.001; odds ratio [OR], 10.30; 95% confidence interval [CI], 2.46 to 43.09), LVD (76.9% versus 0%; P <0.0001; OR, 4.33; 95% CI, 2.14 to 8.74), 3-vessel CAD (51.6% versus 20%; P =0.039; OR, 4.26; 95% CI, 1.16 to 15.69), and LM (100% versus 34%; P =0.019; OR, 1.25; 95% CI, 1.004 to 1.556) were more likely to die. There was no deaths in patients with 2-vessel CAD but they had more nonfatal AMI (43.8% versus 14.3%; OR, 4.667; 95% CI, 1.188 to 18.332).

Conclusions— Patients in whom CABG could not be performed because of ENDCAD had high mortality, especially in the presence of LVD. DM (particularly insulin-dependent), LM CAD, and 3-vessel CAD were independent markers of increased risk.