Clinical Research
Interventional Cardiology
Intracoronary Enalaprilat to Reduce Microvascular Damage During Percutaneous Coronary Intervention (ProMicro) Study

https://doi.org/10.1016/j.jacc.2012.11.025Get rights and content
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Objectives

This study investigated the influence of intracoronary enalaprilat on coronary microvascular function and peri-procedural outcome measures in patients with stable angina undergoing percutaneous coronary intervention (PCI).

Background

Intracoronary angiotensin-converting enzyme inhibitors have been shown to relieve myocardial ischemia in stable patients and to improve epicardial flow in patients with ST-segment elevation myocardial infarction. Yet, it is still unclear whether these effects are mediated by a modulation of the coronary microcirculation.

Methods

We randomly assigned 40 patients to receive either an intracoronary bolus of enalaprilat (50 μg) or placebo before elective PCI. The index of microvascular resistance was measured at baseline, 10 minutes after study drug administration, and after PCI. High-sensitivity cardiac troponin T was measured as a marker of myocardial injury.

Results

Infusion of enalaprilat resulted in a significant reduction in index of microvascular resistance (27 ± 11 at baseline vs. 19 ± 9 after drug vs. 15 ± 8 after PCI), whereas a significant post-procedural increase in index of microvascular resistance levels was observed in the placebo group (24 ± 15 at baseline vs. 24 ± 15 after drug vs. 33 ± 19 after PCI). Index of microvascular resistance levels after PCI were significantly lower in the enalaprilat group (p < 0.001). Patients pre-treated with enalaprilat also showed lower peak values (mean: 21.7 ng/ml, range: 8.2 to 34.8 ng/ml vs. mean: 32.3 ng/ml, range: 12.6 to 65.2 ng/ml, p = 0.048) and peri-procedural increases of high-sensitivity cardiac troponin T (mean: 9.9 ng/ml, range: 2.7 to 19.0 ng/ml vs. mean: 26.6 ng/ml, range: 6.3 to 60.5 ng/ml, p = 0.025).

Conclusions

Intracoronary enalaprilat improves coronary microvascular function and protects myocardium from procedure-related injury in patients with coronary artery disease undergoing PCI. Larger studies are warranted to investigate whether these effects of enalaprilat could result into a significant clinical benefit.

Key Words

angiotensin-converting enzyme inhibitors
coronary artery disease
coronary intervention
coronary microvascular function

Abbreviations and Acronyms

ACE
angiotensin-converting enzyme
CFR
coronary flow reserve
FFR
fractional flow reserve
hs-cTnT
high-sensitivity cardiac troponin T
IMR
index of microvascular resistance
PCI
percutaneous coronary intervention
PMI
periprocedural myocardial infarction

Cited by (0)

Dr. Wijns has relationships with Ablynx, Astra Zeneca, Eli Lilly, GlaxoSmithKline, Therabel, Abbott Vascular, Biotronik, Boston Scientific, Cordis J&J, Edwards, Medtronic, Orbus Neich, St. Jude, and Terumo. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.