Myocardial bridging is an independent predictor of positive spasm provocation testing by intracoronary ergonovine injections: a retrospective observational study

Insights into the invasive diagnostic challenges of coronary artery vasospasm - A systematic review

Coronary provocation testing is an essential diagnostic procedure when evaluating vasospastic angina. Invasive methods using acetylcholine or ergonovine are considered the current gold standard. Despite efforts from global cardiovascular institutions, current protocols vary in dosage, administration time, and procedural approach. In addition, concerns over the specificity of findings and potential complications have limited routine uptake of this procedure in clinical practice. This systematic review evaluates current diagnostic protocols, focusing on invasive provocation testing. We included studies using intracoronary provocation testing with acetylcholine or ergonovine for the assessment of coronary artery vasospasm that detailed specific elements of the procedure (dosage, administration time, etc.) and included ≥50 patients. A total of 28 articles met strict inclusion criteria. Our review highlights the heterogeneity between current diagnostic protocols for invasive provocation testing. We believe standardization of a diagnostic protocol will encourage both current and future cardiologists to incorporate such procedures in the evaluation of variant angina.

The Association Between Myocardial Bridging and Hypertrophic Cardiomyopathy and Their Implications on Percutaneous Coronary Intervention Outcomes: A Retrospective Study

Hypertrophic cardiomyopathy (HCM) is a complex cardiac disorder, often associated with adverse outcomes, including sudden cardiac death. Myocardial bridging (MB), where a coronary artery segment traverses intramurally within the myocardium, complicates coronary blood flow dynamics. This retrospective study investigates the relationship between MB and HCM and their impact on percutaneous coronary intervention (PCI) outcomes. Data from the 2019 National Inpatient Sample (NIS), representing 20% of U.S. hospitalizations, was utilized. Patients with both HCM and MB undergoing PCI were identified and analyzed. The study assessed inpatient outcomes, including mortality, length of stay, hospital cost, and post-PCI complications (atrial fibrillation, acute kidney injury, bleeding, coronary dissection). Patients with HCM and MB exhibited distinct demographics. The study did not find significant associations between HCM/MB and inpatient mortality, length of stay, or hospital cost. However, HCM patients had a higher incidence of atrial fibrillation and acute kidney injury post-PCI (aOR 2.33, 95% CI 1.46 to 3.71, p ≤ 0.001). MB was linked to increased occurrences of acute heart failure (aOR 0.62, 95% CI 0.42-0.92, p = 0.02) and post-PCI bleeding (aOR 4.88, 95% CI 1.17-20.2, p = 0.03). This nationwide study reveals unique demographic profiles for HCM and MB patients. Notably, HCM patients face higher risks of post-PCI complications, including atrial fibrillation and acute kidney injury. These findings provide fresh insights into the MB-HCM relationship and its implications for PCI outcomes. They emphasize the need for tailored interventions and improved patient management in cases involving both HCM and MB.

Prognostic impact of nitrate therapy in patients with myocardial bridge and coexisting coronary artery spasm

The aim of this study was to investigate the prognostic impact of nitrate therapy in patients with myocardial bridge (MB) and coexisting coronary artery spasm (CAS). MB often accompanies CAS. Nitrates have been widely used as anti-ischemic drugs in CAS patients, while it is not recommended in MB patients. Thus, we investigated the long-term impact of nitrate on clinical outcomes in patients with both CAS and MB. A retrospective observational study was performed using propensity score matching (PSM) in a total of 757 consecutive MB patients with positive acetylcholine (Ach) provocation test. Patients were divided into two groups according to the regular administration of nitrates (nitrate group: n = 504, No nitrate group; n = 253). The PSM was used to adjust for selection bias and potential confounding factors, and major clinical outcomes were compared between the two groups up to 5 years. Baseline characteristics were well-matched between the two groups following PSM (n = 211 for both groups). There was no significant difference in the incidence of death, myocardial infarction, and major adverse cardiovascular events (MACEs) between the two groups. However, the nitrate group showed a significantly higher rate of recurrent angina which subsequently needed re-evaluation of coronary arteries by follow-up angiography (15.7 vs. 5.7%, Log-rank p = 0.012) compared to the non-nitrate group. Long-term nitrate administration in patients with MB and coexisting CAS did not show benefit in reducing MACE, rather it was associated with a higher incidence of recurrent angina requiring follow-up angiography.

Effects of carbetocin combined with ergometrine maleate on blood loss and coagulation function of puerperae with postpartum haemorrhage

OBJECTIVE

To determine the effects of carbetocin combined with ergometrine maleate on blood loss and coagulation function of puerperae with postpartum haemorrhage (PH).

METHODS

In this retrospective study, the clinical data of 102 puerperae with PH treated in Harbin Red Cross Central Hospital from March 2019 to February 2022 were analyzed. Among them, 45 puerperae treated with carbetocin alone were assigned to the control group, and the other 57 treated with carbetocin combined ergometrine maleate were assigned to the observation group. After treatment, the blood loss, hemostasis time, changes of coagulation function and hemodynamic indexes, efficacy and incidence of adverse reactions were compared between the two groups.

RESULTS

The blood loss within 2 h and 24 h after treatment and hemostasis time of the observation group were greatly lower than those of the control group (P<0.05). After therapy, the coagulation function-associated indexes (fibrinogen (FIB), prothrombin time (PT), and activated partial thromboplastin time (APTT)) of the two groups were all improved, with greatly better coagulation function-associated indexes in the observation group than those in the control group (all P<0.05). After therapy, the observation group showed notably lower hemodynamic indexes (hear rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP)) than the control group (all P<0.05). Additionally, the observation group yielded a greatly higher effective treatment rate than the control group (P<0.05), and the incidence of adverse reactions in both groups was low, without significant difference (P>0.05).

CONCLUSION

Ergometrine maleate combined with carbetocin can deliver favorable efficacy on PH, because it can effectively reduce the amount and duration of PH, improve the coagulation state of the body, and maintain the stability of hemodynamics, without increasing adverse reactions. Therefore, it is of high application value.

Impact of myocardial bridge on non-culprit vessel lumen changes in patients with acute coronary syndrome

This study aims to clarify the impact of myocardial bridge (MB) on the presence and progression of atherosclerosis in left descending coronary artery (LAD) in patients with acute coronary syndrome (ACS). Ninety-eight patients who underwent percutaneous coronary intervention with the diagnosis of ACS and follow-up coronary angiography but had no significant stenosis in the LAD were included. MB was defined based on coronary angiography. Quantitative coronary angiography was performed to determine the segments where MB was present and proximal to the MB (proximal segment) in patients with MB. In patients without MB, a corresponding region was quantitatively analyzed. The primary endpoint was changes in minimum lumen diameter (MLD) and percentage of diameter stenosis (%DS) in the proximal segment from baseline to follow-up angiography, namely ΔMLD and Δ%DS. MB was identified in 29 (29.6%) patients. Patients with MB had larger MLD and smaller %DS in the proximal segment than their counterpart. During the mean follow-up period of 12.9 ± 5.7 months, MLD and %DS in the proximal segment did not change significantly from baseline to follow-up in patients with and without MB. No significant between-group differences were observed in ΔMLD and Δ%DS. Baseline MLD was identified as the only factor associated with ΔMLD in the proximal segment. ACS patients who had MB but no significant stenosis in the LAD had larger MLD and smaller %DS at the segment proximal to MB compared to those without. In this selected population, serial lumen changes assessed by ΔMLD were not associated with the presence of MB in the LAD.

Endothelial dysfunction in patients with angina and non-obstructed coronary arteries is associated with an increased risk of mayor cardiovascular events. Results of the Spanish ENDOCOR registry

BACKGROUND

Coronary endothelial dysfunction and vasospasm are potential causes of ischemia in patients without obstructive coronary stenoses (INOCA).

OBJECTIVE

To evaluate the prevalence of endothelial dysfunction and the clinical profile of patients with INOCA in Spain, as well as to identify the predictors and the prognostic impact of endothelial dysfunction in this scenario.

METHODS

A total of 438 consecutive patients with INOCA in whom the acetylcholine test was performed were prospectively enrolled. Patients were followed up at 1 and 2 years.

RESULTS

Mean age was 62 ± 11 years with 60% female. Clinical presentation comprised 52.6% angina at rest, 61.2% exertional angina, and 31.7% dyspnea. There were no major complications of the acetylcholine test. Endothelial dysfunction was observed in 198 (45%) of patients, with severe vasoconstriction (defined as over 70% constriction), being observed in 101 (23%). Multivariable regression analysis showed that endothelial dysfunction was predicted by the presence of exertional angina (OR 2.2; CI95%1.01-2.55; p = 0.02), prior coronary disease (OR 2.46; CI95% 1.57-3.89; p < 0.01), and coronary intramyocardial bridging (2.35; CI95% 1.02-5.60; p = 0.04). Patients with endothelial dysfunction presented with worsening angina compared to those without endothelial dysfunction (25.6% vs. 12.8%) and also presented with increased levels of minimal effort angina (40% vs. 26,7%, p = 0.03) more frequently during the follow up than those without endothelial dysfunction. Endothelial dysfunction was also an independent predictor of the occurrence of myocardial infarction or unstable angina at one year (OR 2.85, CI 95% 1.01-9.25; p = 0.03).

CONCLUSIONS

Endothelial dysfunction is present in almost half of patients with INOCA and is associated with worsening symptoms, as well as with a higher rate of adverse events.

Comprehensive functional and anatomic assessment of myocardial bridging: Unlocking the Gordian Knot

Myocardial bridging (MB) is the most frequent congenital coronary anomaly in which a segment of an epicardial coronary artery takes a tunneled course under a bridge of the myocardium. This segment is compressed during systole, resulting in the so-called "milking effect" at coronary angiography. As coronary blood flow occurs primarily during diastole, the clinical relevance of MB is heterogeneous, being usually considered an asymptomatic bystander. However, many studies have suggested its association with myocardial ischemia, anginal symptoms, and adverse cardiac events. The advent of contemporary non-invasive and invasive imaging modalities and the standardization of intracoronary functional assessment tools have remarkably improved our understanding of MB-related ischemia, suggesting the role of atherosclerotic lesions proximal to MB, vasomotor disorders and microvascular dysfunction as possible pathophysiological substrates. The aim of this review is to provide a contemporary overview of the pathophysiology and of the non-invasive and invasive assessment of MB, in the attempt to implement a case-by-case therapeutic approach according to the specific endotype of MB-related ischemia.

The Impact of Myocardial Bridging on the Coronary Functional Test in Patients with Ischaemia with Non-Obstructive Coronary Artery Disease

Background: The possibility of myocardial bridging (MB) causing chest pain has been widely reported; however, the effect of MB on coronary microvessels has not been thoroughly investigated. Therefore, this study evaluated the effects of MB on epicardial coronary artery and coronary microvascular function during coronary angiography (CAG) and coronary function test (CFT) in patients with ischaemia with non-obstructive coronary artery disease (INOCA). Methods: This study included 62 patients with INOCA who underwent CAG and CFT for the left anterior descending coronary artery (LAD) to evaluate chest pain. In the CFT, acetylcholine was first administered intracoronarily in a stepwise manner, followed by chest symptoms, electrocardiographic ST-T changes and CAG. Positive coronary spasm was defined as coronary vasoconstriction of >90% on CAG accompanied by chest symptoms or electrocardiographic ST-T changes. After nitroglycerin administration, CAG was performed to assess MB, which was defined as systolic narrowing of the coronary artery diameter by >20% compared with that in diastole. Coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) were subsequently obtained via transvenous adenosine triphosphate infusion using a pressure wire. Coronary microvascular vasodilatory dysfunction (CMD) was defined as a CFR of <2.0 or an IMR of ≥25 units. Results: Of the 62 patients, 15 (24%) had MB. The patients’ characteristics did not differ between the two groups. Regarding the CAG and CFT results, the presence of coronary spasm in the LAD was higher in the MB (+) group (87%) than in the MB (−) group (53%, p = 0.02), whereas the values of CFR (MB (+): 2.7 ± 1.4, MB (−): 2.8 ± 1.1) and IMR (MB (+): 26.9 ± 1.0, MB (−): 30.0 ± 17.3) and the presence of CMD (MB (+): 53%, MB (−): 60%) were similar in the two groups. Conclusions: The findings suggest that MB predisposes patients with INOCA to coronary spasms. Conversely, MBs may have a limited effect on microvessels, particularly in such patients.

Influence of myocardial bridge on atherosclerotic plaque distribution and characteristics evaluated by near-infrared spectroscopy intravascular ultrasound

BACKGROUND

This study aims to clarify whether myocardial bridge (MB) could influence atherosclerotic plaque characteristics assessed using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) imaging.

METHODS

One hundred and sixteen patients who underwent percutaneous coronary intervention (PCI) using NIRS-IVUS imaging were included. MB was defined as an echo-lucent band surrounding left anterior descending artery (LAD). In MB patients, LAD was divided into three segments: proximal, MB, and distal segments. In non-MB patients, corresponding three segments were defined based on the average length of the above segments. Segmental maximum plaque burden and lipid content derived from NIRS-IVUS imaging in the section of maximum plaque burden were evaluated in each segment. Lipid content of atherosclerotic plaque was evaluated as lipid core burden index (LCBI) and maxLCBI_4mm. LCBI is the fraction of pixels indicating lipid within a region multiplied by 1000, and the maximum LCBI in any 4-mm region was defined as maxLCBI_4mm.

RESULTS

MB was identified in 42 patients. MB was not associated with maximum plaque burden in proximal segment. LCBI and maxLCBI_4mm were significantly lower in patients with MB than those without in proximal segment. Multivariable analysis demonstrated both MB and maximum plaque burden in proximal segment to be independent predictors of LCBI in proximal segment.

CONCLUSIONS

Lipid content of atherosclerotic plaque assessed by NIRS-IVUS imaging was significantly smaller in patients with MB than those without. MB could be considered as a predictor of lipid content of atherosclerotic plaque when assessed by NIRS-IVUS imaging.

Coronary Arterial Function and Disease in Women With No Obstructive Coronary Arteries

Ischemic heart disease (IHD) is the leading cause of mortality in women. While traditional cardiovascular risk factors play an important role in the development of IHD in women, women may experience sex-specific IHD risk factors and pathophysiology, and thus female-specific risk stratification is needed for IHD prevention, diagnosis, and treatment. Emerging data from the past 2 decades have significantly improved the understanding of IHD in women, including mechanisms of ischemia with no obstructive coronary arteries and myocardial infarction with no obstructive coronary arteries. Despite this progress, sex differences in IHD outcomes persist, particularly in young women. This review highlights the contemporary understanding of coronary arterial function and disease in women with no obstructive coronary arteries, including coronary anatomy and physiology, mechanisms of ischemia with no obstructive coronary arteries and myocardial infarction with no obstructive coronary arteries, noninvasive and invasive diagnostic strategies, and management of IHD.

Myocardial bridging presenting as myocardial ischaemia induced cardiac arrest: a case report

Background

Myocardial bridging is a congenital anomaly defined as a segment of epicardial coronary arteries running through the myocardium. Various complications related to myocardial bridging have been reported, but at present, cardiac arrest has rarely been reported.

Case presentation

We report one case of a patient who was successfully resuscitated from ventricular fibrillation cardiac arrest and was diagnosed with myocardial bridging accompanied by myocardial ischaemia. A 50-year-old woman who had been resuscitated from cardiac arrest transferred to our institution for evaluation and management of out-of-hospital cardiac arrest. We confirmed the diagnosis of significant myocardial bridging with evident myocardial ischaemia by coronary angiography, resting echocardiography and heart MRI. Vasospasm was thought to be a trigger factor judging from the transient ST elevation on electrocardiography. In addition, the finding of septal buckling was detected for the first time throughout the whole cardiac cycle by resting echocardiography in MB.

Conclusion

We report a rare case of survival after out-of-hospital cardiac arrest that might be caused by significant myocardial bridging-induced myocardial ischaemia, which was objectively confirmed by echocardiography and heart MRI. Although myocardial bridging is often overlooked as an aetiology for sudden cardiac death, this case highlights the importance of expanding the differential diagnosis to myocardial bridging in the work-up for the cause of sudden cardiac death.

Vasospastic angina: pathophysiology and clinical significance

The review discusses an analysis of the literature on various aspects of the pathogenesis, diagnosis and treatment of vasospastic angina (VA). Data on the prevalence of coronary artery spasm (CAS) in various populations, as well as risk factors and triggers, are presented. We considered pathophysiological mechanisms of CAS, including hyperreactivity of coronary smooth muscle cells, endothelial dysfunction, nonspecific inflammation, oxidative stress, magnesium deficiency, autonomic imbalance, etc. The relationship of CAS with coronary atherosclerosis and thrombosis is emphasized. Modern recommendations for the diagnosis and treatment of VA are presented. Invasive verification of CAS is performed by pharmacological provocation tests with certain contraindications. Calcium antagonists and their combination with long-acting nitrates play a key role in the treatment of VA. Medications with a prospect for use in VA are Rho-kinase inhibitors, ATP-sensitive potassium channel activators, alpha-1 blockers. The management of patients with refractory VA and the prospects for endovascular treatment are discussed. It was noted that patients with multi-vessel VA are more likely to develop life-threatening arrhythmias and sudden death.