Clinical and laboratory characteristics in patients with acute myocardial infarction due to occlusive vasospasm

Clinical Outcomes of Vasospastic Angina Patients Presenting With Acute Coronary Syndrome

BACKGROUND

Coronary vasospasm is an important pathogenesis of acute coronary syndrome (ACS). However, the clinical features and prognosis of vasospastic angina (VA) patients presenting with ACS (VAACS) are still unclear. We aimed to evaluate the clinical characteristics and long-term outcomes of VAACS patients without significant coronary artery stenosis.

METHODS AND RESULTS

A total of 986 VA patients confirmed by ergonovine provocation test were analyzed. VAACS was defined as VA patients visiting the emergency room with documented electrocardiographic changes, significant arrhythmias, or elevated cardiac biomarkers. VA patients with elevated cardiac biomarkers were further considered to have myocardial infarction (MI; VAMI). During 4.4 years of median follow-up, we investigated major adverse cardiac events including cardiac death, MI, revascularization, and rehospitalization because of recurrent angina. The VAACS group consisted of 149 patients (15.1%), and VAMI occurred in 81 patients (8.2%). VAACS patients were younger and had a higher prevalence of diabetes mellitus, MI history, and higher levels of inflammatory markers compared with non-VAACS patients. In multivariable Cox regression analyses, VAACS patients were associated with an increased risk of major adverse cardiac events (hazard ratio, 1.65; 95% CI 1.14-2.37; P=0.007) and recurrent MI hazard ratio, 2.57; 95% CI, 1.35-4.87; P=0.004). In addition, VAMI patients had an increased risk of major adverse cardiac events (hazard ratio, 1.75; 95% CI, 1.11-2.76; P=0.016) and recurrent MI (hazard ratio, 2.43; 95% CI, 1.09-5.40; P=0.03).

CONCLUSION

VAACS patients showed worse clinical outcomes, driven mainly by recurrent MI. Therefore, intensive medical treatment might be required in VAACS patients.

Overview of the pharmacological spasm provocation test: Comparisons between acetylcholine and ergonovine

The spasm provocation tests of ergonovine and acetylcholine have been employed in the cardiac catheterization laboratory. Ergonovine acts through the serotogenic receptors, while acetylcholine acts through the muscarinic cholinergic receptors. Different mediators may have the potential to cause different coronary responses. However, there are few reports concerning the coronary response between ergonovine and acetylcholine in the same patients. Acetylcholine is supersensitive for females; spasm provoked by ergonovine is focal and proximal, whereas provoked spasm by acetylcholine is diffuse and distal. We should use both tests as supplementary in the clinic because ergonovine and acetylcholine have self-limitations to induce coronary spasms during daily life. The maximal pharmacological doses, administration methods, and the angiographical positive definition are remarkably different for each institution in the world. We recommend the pharmacological spasm provocation tests as Class I in the guidelines in patients with vasospastic angina throughout the world.