Chronic total coronary occlusion is among the most complex coronary artery diseases. Elevated homocysteine is a risk factor for coronary artery diseases. However, few studies have assessed the relationship between homocysteine and chronic total coronary occlusion.

1295 individuals from Southwest China were enrolled in the study. Chronic total coronary occlusion was defined as complete occlusion of coronary artery for more than three months. Homocysteine was divided into quartiles according to its level. Univariate and multivariate logistic regression models, receiver operating characteristic curves, and subgroup analysis were applied to assess the relationship between homocysteine and chronic total coronary occlusion.

Subjects in the higher homocysteine quartile had a higher rate of chronic total coronary occlusion (P < 0.001). After adjustment, the odds ratio for chronic total coronary occlusion in the highest quartile of homocysteine compared with the lowest was 1.918 (95% confidence interval 1.237–2.972). Homocysteine ≥ 15.2 μmol/L was considered an independent indicator of chronic total coronary occlusion (odds ratio 1.53, 95% confidence interval 1.05–2.23; P = 0.0265). The area under the receiver operating characteristic curve was 0.659 (95% confidence interval, 0.618–0.701; P < 0.001). Stronger associations were observed in elderly and in those with hypertension and diabetes.

Elevated homocysteine is significantly associated with chronic total coronary occlusion, particularly in elderly and those with hypertension and diabetes.

This study was designed to investigate the potential existence of the response of neurons in the parafascicular nucleus of the thalamus to acute myocardial ischaemia induced by selective coronary artery occlusion and the effects of midazolam on the response in rats.

The left anterior descending branch of the coronary artery was instrumented with a snare occluder in anaesthetized Sprague-Dawley rats. A single-barrel glass microelectrode was used for recording the unit discharges of the neuron in the parafascicular nucleus. The neuron responding only to noxious somatic stimulation was further examined for the response to coronary artery occlusion. Once the effect of coronary artery occlusion on the discharges was detected, the pharmacological effects of midazolam and flumazenil were examined.

It was observed that the discharge rate of the neuron was markedly increased following coronary artery occlusion. Midazolam attenuated the increase in the discharges of the neuron induced by coronary artery occlusion (P < 0.05). The effect of midazolam was reversed by flumazenil.

The parafascicular nucleus is involved in the modulation of cardiac nociception and midazolam possesses antinociceptive property in modulating cardiac pain.