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Effects of Nicorandil, Isosorbide Mononitrate, or Diltiazem on Radial Artery Grafts After CABG: The Randomized
Yunpeng Zhu1, Wei Zhang2, Kaijie Qin1
1Department of Cardiovascular Surgery, Ruijin Hospital Shanghai Jiao Tong University School of Medicine, China (Y.Z., K.Q., Y.L., H.Y., Z.W., X.Y., M.Z., H.L., J.Q., H.X., Y.S., Q.Z.).
Insights
Nicorandil and isosorbide mononitrate showed lower radial artery graft failure rates compared to diltiazem after coronary artery bypass grafting. Further trials are needed to confirm these findings for optimal antispastic treatment.
Area of Science:
- Cardiology
- Vascular Surgery
- Pharmacology
Background:
- Optimal antispastic treatment for radial artery (RA) grafts post-coronary artery bypass grafting (CABG) remains unclear.
- This study provides pilot comparative data on nicorandil, isosorbide mononitrate, and diltiazem for RA graft management.
Purpose of the Study:
- To compare the efficacy of nicorandil, isosorbide mononitrate, and diltiazem in preventing radial artery graft failure after coronary artery bypass grafting.
- To generate pilot data for future hypothesis-testing trials on antispastic treatments for RA grafts.
Main Methods:
- A single-center, randomized, open-label, parallel-group pilot trial involving 150 patients undergoing CABG with RA grafts.
- Patients received oral nicorandil (15 mg/day), isosorbide mononitrate (50 mg/day), or diltiazem (180 mg/day) for 24 weeks.
- Radial artery graft failure was assessed using coronary computed tomography angiography at 1 and 24 weeks post-surgery.
Main Results:
- At 24 weeks, RA graft failure rates were lower with nicorandil (16.1%) and isosorbide mononitrate (12.5%) compared to diltiazem (27.8%).
- Isosorbide mononitrate showed a statistically significant reduction in RA graft failure compared to diltiazem (difference, -15.3% [95% CI, -29.8% to -0.2%]).
- Nicorandil also demonstrated a trend towards lower RA graft failure compared to diltiazem at 24 weeks (difference, -11.7% [95% CI, -26.6% to 3.4%]).
Conclusions:
- Nicorandil and isosorbide mononitrate treatments were associated with reduced radial artery graft failure rates compared to diltiazem.
- These findings suggest potential benefits of nicorandil and isosorbide mononitrate in maintaining RA graft patency post-CABG.
- Larger, hypothesis-testing trials are recommended to validate these results and establish optimal antispastic treatment strategies.
Background:
The optimal antispastic treatment after coronary artery bypass grafting using radial artery (RA) grafts is controversial. This clinical trial aimed to generate pilot comparative data on the effects of nicorandil, isosorbide mononitrate, or diltiazem on RA grafts.
Methods:
This was a single-center, randomized, open-label, parallel-group pilot trial. Eligible patients who underwent coronary artery bypass grafting using RA grafts were randomized in a 1:1:1 ratio to receive oral nicorandil (15 mg daily), isosorbide mononitrate (50 mg daily), or diltiazem (180 mg daily) for 24 weeks post-coronary artery bypass grafting. The primary outcome was RA graft failure (modified Fitzgibbon grade B, S, or O) at 1 and 24 weeks, assessed by coronary computed tomography angiography.
Results:
Among 150 randomized participants, 149 (mean age, 56.8 years; 13.4% women) with 177 RA grafts were assessed at least once by coronary computed tomography angiography, including 50 participants with 64 RA grafts in the nicorandil group, 50 participants with 57 RA grafts in the isosorbide mononitrate group, and 49 participants with 56 RA grafts in the diltiazem group, respectively. At 1 week post-coronary artery bypass grafting, the RA graft failure rates were lower with nicorandil versus diltiazem (19.4% versus 25.0%; difference, -5.6% [95% CI, -20.6% to 9.3%]) and isosorbide mononitrate versus diltiazem (18.2% versus 25.0%; difference, -6.8% [95% CI, -21.8% to 8.6%]). The RA graft failure rates were slightly higher with nicorandil versus isosorbide mononitrate (19.4% versus 18.2%; difference, 1.2% [95% CI, -13.3% to 15.2%]). At 24 weeks, RA graft failure rates were lower with nicorandil versus diltiazem (16.1% versus 27.8%; difference, -11.7% [95% CI, -26.6% to 3.4%]), and isosorbide mononitrate versus diltiazem (12.5% versus 27.8%; difference, -15.3% [95% CI, -29.8% to -0.2%]), and slightly higher with nicorandil versus isosorbide mononitrate (16.1% versus 12.5%; difference, 3.6% [95% CI, -9.6% to 16.4%]).
Conclusions:
In this pilot trial, treatment with nicorandil or isosorbide mononitrate was associated with a lower RA graft failure rate compared with diltiazem. Larger hypothesis-testing trials are warranted.
Registration:
URL: https://www.clinicaltrials.gov; Unique identifier: NCT04310995.
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