Characterization and implications of intracoronary hemodynamic assessment during coronary spasm provocation testing.

BACKGROUND: Current diagnostic criteria for coronary spasm are based on patient's symptoms, ECG shifts and epicardial vasoconstriction during acetylcholine (ACh) spasm testing. AIMS: To assess the feasibility and diagnostic value of coronary blood flow (CBF) and resistance (CR) assessment as objective parameters during ACh testing. METHODS: Eighty-nine patients who underwent intracoronary reactivity testing including ACh testing with synchronous Doppler wire-based measurements of CBF and CR were included. Coronary microvascular and epicardial spasm, respectively, were diagnosed based on COVADIS criteria. RESULTS: Patients were 63 ± 13 years old, predominantly female (69%) and had preserved LV ejection fraction (64 ± 8%). Overall, assessment of CBF and CR during ACh testing revealed a decrease in CBF of 0.62 (0.17-1.53)-fold and an increase of CR of 1.45 [0.67-4.02]-fold in spasm patients compared to 2.08 (1.73-4.76) for CBF and 0.45 (0.44-0.63) for CR in patients without coronary spasm (both p < 0.01). Receiver operating characteristic revealed a high diagnostic ability of CBF and CR (AUC 0.86, p < 0.001, respectively) in identifying patients with coronary spasm. However, in 21% of patients with epicardial spasm and 42% of patients with microvascular spasm a paradoxical response was observed. CONCLUSIONS: This study demonstrates feasibility and potential diagnostic value of intracoronary physiology assessments during ACh testing. We observed opposite responses of CBF and CR to ACh in patients with positive vs. negative spasm test. While a decrease in CBF and an increase in CR during ACh seem pathognomonic for spasm, some patients with coronary spasm demonstrate paradoxical ACh response demanding further scientific investigations.

Safety assessment and results of coronary spasm provocation testing in patients with myocardial infarction with unobstructed coronary arteries compared to patients with stable angina and unobstructed coronary arteries.

BACKGROUND: Coronary spasm is an established cause for myocardial infarction with unobstructed coronary arteries, and can be diagnosed using intracoronary acetylcholine testing. However, it has been questioned whether such testing is feasible and safe in the acute phase. The aim of this study was to assess the frequency of coronary spasm and the safety of the acetylcholine test in patients with myocardial infarction with unobstructed coronary arteries compared to patients with stable angina and unobstructed coronaries. METHODS: One hundred and eighty selected patients (52% women, mean age 62±13 years) with either myocardial infarction with unobstructed coronary arteries (n=80) or stable angina and unobstructed coronaries (n=100) were enrolled from 2007-2018. All patients underwent the acetylcholine test according to a standardised protocol immediately after diagnostic angiography. Apart from assessment of clinical, demographic and risk factor data, side effects and complications during the acetylcholine test were recorded. RESULTS: Overall, epicardial spasm was found in 26% with a higher prevalence among the myocardial infarction with unobstructed coronary arteries compared to the stable angina patients (35% vs 19%, p=0.017). Microvascular spasm was found in 42% with a higher prevalence among the stable patients compared to the myocardial infarction with unobstructed coronary arteries cohort (53% vs 29%, p=0.0014). There were no statistically significant differences in the rate of side effects (16% vs 14%, p=0.674) or complications (1% vs 2.5%, p=0.438) between the two groups. None of the patients experienced irreversible complications. CONCLUSION: Coronary spasm is a frequent cause for myocardial infarction with unobstructed coronary arteries. Spasm provocation testing using acetylcholine is feasible in such patients in the acute phase. The complication rate during acetylcholine testing in myocardial infarction with unobstructed coronary arteries patients is low and comparable to patients with stable angina.

Safety assessment and results of coronary spasm provocation testing in patients with myocardial infarction with unobstructed coronary arteries compared to patients with stable angina and unobstructed coronary arteries.

BACKGROUND: Coronary spasm is an established cause for myocardial infarction with unobstructed coronary arteries, and can be diagnosed using intracoronary acetylcholine testing. However, it has been questioned whether such testing is feasible and safe in the acute phase. The aim of this study was to assess the frequency of coronary spasm and the safety of the acetylcholine test in patients with myocardial infarction with unobstructed coronary arteries compared to patients with stable angina and unobstructed coronaries. METHODS: One hundred and eighty selected patients (52% women, mean age 62±13 years) with either myocardial infarction with unobstructed coronary arteries (n=80) or stable angina and unobstructed coronaries (n=100) were enrolled from 2007-2018. All patients underwent the acetylcholine test according to a standardised protocol immediately after diagnostic angiography. Apart from assessment of clinical, demographic and risk factor data, side effects and complications during the acetylcholine test were recorded. RESULTS: Overall, epicardial spasm was found in 26% with a higher prevalence among the myocardial infarction with unobstructed coronary arteries compared to the stable angina patients (35% vs 19%, p=0.017). Microvascular spasm was found in 42% with a higher prevalence among the stable patients compared to the myocardial infarction with unobstructed coronary arteries cohort (53% vs 29%, p=0.0014). There were no statistically significant differences in the rate of side effects (16% vs 14%, p=0.674) or complications (1% vs 2.5%, p=0.438) between the two groups. None of the patients experienced irreversible complications. CONCLUSION: Coronary spasm is a frequent cause for myocardial infarction with unobstructed coronary arteries. Spasm provocation testing using acetylcholine is feasible in such patients in the acute phase. The complication rate during acetylcholine testing in myocardial infarction with unobstructed coronary arteries patients is low and comparable to patients with stable angina.