Ischemia With Nonobstructive Coronary Artery Disease: Concept, Assessment, and Management

The Use of Precision Epigenetic Methods for the Diagnosis and Care of Stable Coronary Heart Disease Reduces Healthcare Costs

INTRODUCTION

The cost of secondary prevention of coronary heart disease (CHD) is continuing to increase, with a substantial portion of this acceleration being driven by the expense of confirmatory diagnostic testing. Conceivably, newly developed precision epigenetic technologies could drive down these costs. However, at the current time, their impact on overall expense for CHD care is poorly understood. We hypothesized that the use of a newly developed, highly sensitive, and specific epigenetic test, PrecisionCHD, could decrease the costs of secondary prevention.

METHODS

To test this hypothesis, we constructed a budget impact analysis using a cost calculation model that examined the effects of substituting PrecisionCHD for conventional CHD diagnostic tests on the expenses of the initial evaluation and first year of care of stable CHD using a 1-year time horizon with no discounting.

RESULTS

The model projected that for a commercial insurer with one million members, full adoption of PrecisionCHD as the primary method of initial CHD assessment would save approximately $113.6 million dollars in the initial year.

CONCLUSION

These analyses support the use of precision epigenetic methods as part of the initial diagnosis and care of stable CHD and can meaningfully reduce cost. Real-world pilots to test the reliability of these analyses are indicated.

Nonobstructive epicardial coronary artery disease: an evolving concept in need of diagnostic and therapeutic guidance

For decades, we have been treating patients presenting with angina and concerning electrocardiographic changes indicative of ischemia or injury, in whom no culprit epicardial coronary stenosis was found during diagnostic coronary angiography. Unfortunately, the clinical outcomes of these patients were not better than those with recognized obstructive coronary disease. Improvements in technology have allowed us to better characterize these patients. Consequently, an increasing number of patients with ischemia and no obstructive coronary artery disease (INOCA) or myocardial infarction in the absence of coronary artery disease (MINOCA) have now gained formal recognition and are more commonly encountered in clinical practice. Although both entities might share functional similarities at their core, they pose significant diagnostic and therapeutic challenges. Unless we become more proficient in identifying these patients, particularly those at higher risk, morbidity and mortality outcomes will not improve. Though this field remains in constant flux, data continue to become available. Therefore, we thought it would be useful to highlight important milestones that have been recognized so we can all learn about these clinical entities. Despite all the progress made regarding INOCA and MINOCA, many important knowledge gaps continue to exist. For the time being, prompt identification and early diagnosis remain crucial in managing these patients. Even though we are still not clear whether intensive medical therapy alters clinical outcomes, we remain vigilant and wait for more data.

Ranolazine for improving coronary microvascular function in patients with nonobstructive coronary artery disease: a systematic review and meta-analysis with a trial sequential analysis of randomized controlled trials

Background

Microvascular dysfunction in patients with nonobstructive coronary artery disease is increasingly being recognized as an important health issue. This systematic review and meta-analysis evaluated the effectiveness of ranolazine, an antianginal agent, in improving coronary microvascular function.

Methods

We conducted a comprehensive literature search of the Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure, the Chinese BioMedical Literature Database, and gray literature databases until September 30, 2023. The included studies were randomized controlled trials (RCTs) published in the English or Chinese languages that screened for eligibility using two independent investigators. Risk of bias was evaluated with the Cochrane Collaboration tool. Subgroup and sensitivity analyses were used to identify sources of heterogeneity. Meta-analysis was performed using RevMan version 5.4 (Cochrane) and Stata version 16.0 (StataCorp).

Results

From 1,470 citations, 8 RCTs involving 379 participants were included in this analysis. Our findings showed that ranolazine increased coronary flow reserve (CFR) over an 8 to 12-week follow-up period [standardized mean difference =1.16; 95% confidence interval (CI): 0.4-1.89; P=0.002]. Ranolazine increased the global myocardial perfusion reserve index (MPRI) [weighted mean difference (WMD) =0.18; 95% CI: 0.07-0.29; P=0.002] and the midsubendocardial MPRI (WMD =0.10; 95% CI: 0.02-0.19; P=0.02). Moreover, ranolazine improved 3 of the 5 Seattle Angina Questionnaire scores, namely, physical functioning (WMD =4.89; 95% CI: 0.14 to 9.64; P=0.04), angina stability (WMD =17.31; 95% CI: 7.13-27.49; P=0.0009), and quality of life (WMD =10.11; 95% CI: 3.57-16.65; P=0.0003). Trial sequential analysis showed that the meta-analysis of angina stability and quality of life scores had a sufficient sample size and statistical power.

Conclusions

Our analysis suggests that ranolazine is associated with improvements in CFR, myocardial perfusion, and the Seattle Angina Questionnaire scores in patients with nonobstructive coronary artery disease. However, further large-scale RCTs with long-term follow-up are recommended to validate these findings and provide a more comprehensive understanding of the effects of ranolazine on coronary microvascular function.

Causal Relationship between Angina and Hepatic Failure as Revealed by Mendelian Randomization

BACKGROUND

Patients with angina are often suffering from comorbidities such as varying degrees of hepatic dysfunction. However, the impact of angina on the incidence of hepatic failure (HF) remains unclear.

METHODS

The genetic data were retrieved from genome-wide association studies. Five Mendelian randomization methods were used to investigate the causal relationship between unstable angina (UA), stable angina (SA), and HF. The result of the Inverse variance weighted (IVW) method was deemed the principal result. In addition, we performed a comprehensive sensitivity analysis to verify the robustness of the results.

RESULTS

The IVW results showed that UA (Odds ratio (OR): 2.055, 95% confidence interval (CI): 1.171-3.606, p = 0.012) was causally associated with the incidence of HF. SA (OR: 1.122, 95% CI: 0.738-1.706, p = 0.591) was not causally associated with the incidence of HF. Sensitivity analysis did not identify any bias in the results.

CONCLUSIONS

UA turned out to be a risk factor for HF. SA does not have a significant causal effect on HF. Therefore, it is highly recommended that patients with chronic liver disease seek prompt medical attention and undergo regular monitoring of liver function when experiencing UA. This may help them to reduce the risk of HF.

Vasospastic angina: a review on diagnostic approach and management

Vasospastic angina (VSA) refers to chest pain experienced as a consequence of myocardial ischaemia caused by epicardial coronary spasm, a sudden narrowing of the vessels responsible for an inadequate supply of blood and oxygen. Coronary artery spasm is a heterogeneous phenomenon that can occur in patients with non-obstructive coronary arteries and obstructive coronary artery disease, with transient spasm causing chest pain and persistent spasm potentially leading to acute myocardial infarction (MI). VSA was originally described as Prinzmetal angina or variant angina, classically presenting at rest, unlike most cases of angina (though in some patients, vasospasm may be triggered by exertion, emotional, mental or physical stress), and associated with transient electrocardiographic changes (transient ST-segment elevation, depression and/or T-wave changes). Ischaemia with non-obstructive coronary arteries (INOCA) is not a benign condition, as patients are at elevated risk of cardiovascular events including acute coronary syndrome, hospitalization due to heart failure, stroke and repeat cardiovascular procedures. INOCA patients also experience impaired quality of life and associated increased healthcare costs. VSA, an endotype of INOCA, is associated with major adverse events, including sudden cardiac death, acute MI and syncope, necessitating the study of the most effective treatment options currently available. The present literature review aims to summarize current data relating to the diagnosis and management of VSA and provide details on the sequence that treatment should follow.