Time-Dependent Analysis of Blood Sampling to Detect Metabolic Ischemia　- Serial Coronary Artery-Coronary Sinus Lactate Analysis During Acetylcholine Provocation.

BACKGROUND

The optimal timing for lactate sampling during acetylcholine (ACh) provocation to detect metabolic ischemia remains unclear.

METHODS AND

RESULTS

In 20 patients with suspected INOCA, blood samples from the coronary artery and coronary sinus were obtained at baseline, every minute for 5 min after ACh, and after nitroglycerin. Metabolic ischemia (negative lactate extraction ratio) occurred in 12 patients: 10 patients exhibited ischemia at 1 min, and 2 patients only at 2 min. No ischemia was observed beyond 3 min.

CONCLUSIONS

Sampling at both 1 and 2 min may reduce false-negative detection of metabolic ischemia during ACh provocation.