Despite successful reperfusion after large myocardial infarction (MI), bioabsorbable cardiac matrix did not reduce adverse left ventricular (LV) remodeling or cardiac events, according to data published in the Journal of the American College of Cardiology.

In PRESERVATION I (Prevention of Remodeling of the Ventricle and Congestive Heart Failure After Acute Myocardial Infarction) clinical trial, Sunil V. Rao, MD, of the Duke Clinical Research Institute in Durham, North Carolina, and colleagues compared bioabsorbable cardiac matrix against saline to analyze LV dilation and adverse events between baseline and 6 months.

“Bioabsorbable cardiac matrix is an aqueous mixture of 1% sodium alginate and 0.3% calcium gluconate,” the authors wrote. “It is a sterile, colorless liquid that is not cytotoxic or mutagenic. Its mechanism of action involves assembling into a flexible gel that structurally resembles ECM [extracellular matrix] when exposed to excess ionized calcium present in infarcted myocardium.”

Investigators studied 303 patients who, despite successful percutanous coronary intervention (PCI) of ST-segment elevation MI (STEMI), still had large areas of infarction. Patients were randomly assigned 2:1 to bioabsorbable cardiac matrix or saline (n=201 and n=102, respectively) injected into the infarct-related artery 2 to 5 days after PCI.

The mean change in LV end-diastolic volume index (LVEDVI) from baseline to 6 months was the primary outcome. Secondary outcomes included changes in Kansas City Cardiomyopathy Questionnaire score, 6-minute walk time, and New York Heart Association function class. A composite of cardiovascular death, recurrent MI, target vessel revascularization, stent thrombosis, significant arrhythmia that required therapy, or myocardial rupture served as the primary safety end point.

Between the 2 groups, there was no significant change in LVEDVI from baseline to 6 months (mean change ± SD: cardiac matrix: 14.1 ± 28.9 mL/m2 vs saline: 11.7 ± 26.9 mL/m2; P=.49). Differences in secondary end points were also nonsignificant, and the primary safety outcomes were similar between groups (cardiac matrix: 11.6% vs saline: 9.1%; P=.37).

In an analysis limited to patients who could walk both at baseline and at 6 months (n=129 assigned to BCM; n=67 assigned to saline), the authors found a significant improvement in the bioresorbable cardiac matrix group (mean change in 6-minute walking test BCM 149.4 m vs saline: 94.6; P=.003).

“This study has several limiting factors, including a lack of benefit,” investigators noted. “First, the volume of BCM might not have been high enough for the large infarctions included in this trial … Second, our study population might have been a limiting factor: In subjects with very large infarctions, it is possible that remodeling simply cannot be prevented … Third, the trial did not test whether more acute deployment of BCM (eg, during primary PCI) might vary its impact.”

However, since bioabsorbable cardiac matrix did improve some functional outcomes (eg, 6-minute walking test), the authors suggested focusing on research that examines the treatment’s impact on exercise capacity as well as thromboembolic events.

Reference

Rao SV, Zeymer U, Douglas PS, et al. Bioabsorbable intracoronary matrix for prevention of ventricular remodeling after myocardial infarction. J Am Coll Cardiol. 2016;68(7):715-723. doi: 10.1016/j.jacc.2016.05.053.