Angina relates to coronary flow in women with ischemia and no obstructive coronary artery disease

Effect of Aficamten on Health Status Outcomes in Obstructive Hypertrophic Cardiomyopathy: Results from SEQUOIA-HCM

BACKGROUND

A primary goal in treating obstructive hypertrophic cardiomyopathy (oHCM) is to improve patients' health status: their symptoms, function, and quality of life. The health status benefits of aficamten, a novel cardiac myosin inhibitor, have not been comprehensively described.

OBJECTIVES

This study sought to determine the effect of aficamten on patient-reported health status, including symptoms of fatigue, shortness of breath, chest pain, physical and social limitations, and quality of life.

METHODS

SEQUOIA-HCM (Phase 3 Trial to Evaluate the Efficacy and Safety of Aficamten Compared to Placebo in Adults With Symptomatic oHCM) randomized symptomatic adults with oHCM to 24 weeks of aficamten (n = 142) or placebo (n = 140), followed by a 4-week washout. The Kansas City Cardiomyopathy Questionnaire (KCCQ) and Seattle Angina Questionnaire 7-item (SAQ7) were serially administered. Changes in mean KCCQ-Overall Summary Score (KCCQ-OSS) and SAQ7-Summary Score (SAQ7-SS) from baseline to 24 weeks and following treatment withdrawal were compared using linear regression adjusted for baseline scores and randomization strata. Proportions of patients with clinically important changes were compared.

RESULTS

Among 282 participants, the mean age was 59 ± 13 years, 115 (41%) were female, and 223 (79%) were White. Baseline KCCQ-OSS (69.3 ± 20.1 vs 67.3 ± 18.8) and SAQ7-SS (72.0 ± 21.0 vs 72.4 ± 18.3) were similar between aficamten and placebo groups. Treatment with aficamten, compared with placebo, improved both the mean KCCQ-OSS (13.3 ± 16.3 vs 6.1 ± 12.6; mean difference: 7.9; 95% CI: 4.8-11.0; P < 0.001) and SAQ7-SS (11.6 ± 17.4 vs 3.8 ± 14.4; mean difference: 7.8; 95% CI: 4.7-11.0; P < 0.001) at 24 weeks, with benefits emerging within 4 weeks. No heterogeneity in treatment effect was found across subgroups. A much larger proportion of participants experienced a very large health status improvement (≥20 points) with aficamten vs placebo (KCCQ-OSS: 29.7% vs 12.4%, number needed to treat: 5.8; SAQ7-SS: 31.2% vs 13.9%, number needed to treat: 5.8). Participants' health status worsened significantly more after withdrawal from aficamten than placebo (KCCQ-OSS: -16.2 ± 19.0 vs -3.0 ± 9.6; P < 0.001; SAQ7-SS: -17.4 ± 21.4 vs -2.5 ± 13.3), further confirming a causal effect of aficamten.

CONCLUSIONS

In patients with symptomatic oHCM, treatment with aficamten resulted in markedly improved health status, including significant improvement in chest pain-related health status, than placebo. (Phase 3 Trial to Evaluate the Efficacy and Safety of Aficamten Compared to Placebo in Adults With Symptomatic oHCM [SEQUOIA-HCM]; NCT05186818).

Coronary Flow Reserve Changes after Angiotensin Receptor-Neprilysin Inhibitor Treatment in Heart Failure with Reduced Ejection Fraction

Background

Sacubitril/valsartan has been shown to reduce hospital admissions and even mortality for heart failure. In heart failure and acute coronary syndrome, the effects of sacubitril/valsartan have been studied, but the effect on coronary artery flow is not known.

Objective

We aimed to understand the effect of sacubitril/valsartan on coronary artery flow by using echocardiographic coronary flow reserve (CFR).

Methods

Thirty-six patients (17 ischemic and 19 non-ischemic) with heart failure with reduced ejection fraction (EF of < 40%) eligible for sacubitril/valsartan treatment and 21 normal controls were recruited. The study group and controls were similar with regard to gender, smoking status, and age distribution (p = 0.874, p = 0.709, and p = 0.765, respectively). Blood pressure, heart rate, 6-minute walk test (6MWT), N terminal pro B type natriuretic peptide (NT-pro-BNP) level, standard echocardiography, from where left anterior descending mid-distal flow was seen, baseline peak diastolic flow rate and 2 minutes after dipyridamole infusion, and hyperemic peak diastolic flow rate were measured, and CFR with echocardiography was assessed prior to and at 6 months after sacubitril/valsartan initiation.

Results

Baseline peak diastolic flow rate did not exhibit a significant difference at 6 months (p = 0.143), but hyperemic peak diastolic flow rate, CFR, EF (%), and 6MWD values were significantly increased (all p < 0.001), and New York Heart Association Functional Class, NT-pro-BNP (pg/mL), left ventricule end diastolic diameter (mm), and left ventricule end systolic diameter (mm) values were significantly decreased (all p < 0.001) after sacubitril/valsartan treatment.

Conclusions

Sacubitril/valsartan significantly alters coronary blood flow, especially its dynamic features, in patients with heart failure with reduced ejection fraction.

Continuous Versus Bolus Thermodilution-Derived Coronary Flow Reserve and Microvascular Resistance Reserve and Their Association With Angina and Quality of Life in Patients With Angina and Nonobstructive Coronaries: A Head-to-Head Comparison

Background Coronary flow reserve (CFR) and microvascular resistance reserve (MRR) are physiological parameters to assess coronary microvascular dysfunction. CFR and MRR can be assessed using bolus or continuous thermodilution, and the correlation between these methods has not been clarified. Furthermore, their association with angina and quality of life is unknown. Methods and Results In total, 246 consecutive patients with angina and nonobstructive coronary arteries from the multicenter Netherlands Registry of Invasive Coronary Vasomotor Function Testing (NL-CFT) were investigated. The 36-item Short Form Health Survey Quality of Life and Seattle Angina questionnaires were completed by 153 patients before the invasive measurements. CFR and MRR were measured consecutively with bolus and continuous thermodilution. Mean continuous thermodilution-derived coronary flow reserve (CFRabs) was significantly lower than mean bolus thermodilution-derived coronary flow reserve (CFRbolus) (2.6±1.0 versus 3.5±1.8; P<0.001), with a modest correlation (ρ=0.305; P<0.001). Mean continuous thermodilution-derived microvascular resistance reserve (MRRabs) was also significantly lower than mean bolus thermodilution-derived MRR (MRRbolus) (3.1±1.1 versus 4.2±2.5; P<0.001), with a weak correlation (ρ=0.280; P<0.001). CFRbolus and MRRbolus showed no correlation with any of the angina and quality of life domains, whereas CFRabs and MRRabs showed a significant correlation with physical limitation (P=0.005, P=0.009, respectively) and health (P=0.026, P=0.012). In a subanalysis in patients in whom spasm was excluded, the correlation further improved (MRRabs versus physical limitation: ρ=0.363; P=0.041, MRRabs versus physical health: ρ=0.482; P=0.004). No association with angina frequency and stability was found. Conclusions Absolute flow measurements using continuous thermodilution to calculate CFRabs and MRRabs weakly correlate with, and are lower than, the surrogates CFRbolus and MRRbolus. Absolute flow parameters showed a relationship with physical complaints. No relationship with angina frequency and stability was found.

Coronary Collateral Circulation: A New Predictor of Mortality in Heart Transplant Recipients With Allograft Vasculopathy

Coronary collateral arteries (CCAs) are anastomotic channels between vessels; although beneficial in atherosclerosis, their role in heart transplantation (HT) recipients is underinvestigated. CCAs initially develop as microcirculation and cardiac allograft vasculopathy (CAV), promoting immune-dependent proliferative angiogenic response, and play a role in their development. In our hypothesis, ischemia induced by coronary microvascular dysfunction (CMD) triggers the development of CCAs, which are, in turn, less functional as affected by CAV themselves.

Methods

One hundred twenty-one patients receiving HT at our institution were retrospectively evaluated and were included if transthoracic echocardiography with coronary flow velocity reserve (CFVR) assessment and coronary angiography were performed. CMD was defined as CFVR of ≤2.5. Patients with CAV were enrolled, and their angiograms were reviewed to evaluate the presence of CCAs. Cardiovascular mortality was assessed as the main clinical outcome.

Results

Forty patients were found to have CCAs. Patients with CCAs have lower CFVR than those without CCAs (2.22 ± 0.72 versus 2.69 ± 0.92;P = 0.003), reflecting in different rates of CMD in the 2 groups (72.5% versus 37%; P < 0.001). CMD is associated with higher CAV grades (P < 0.001), which are also associated with CCAs (P < 0.001). Patients with poorly developed CCAs have lower CFVR (P < 0.001). At multivariable analysis, CMD (P = 0.008) and higher CAV grades (P = 0.005) are independent predictors of CCAs. During the median follow-up time of 10.2 (6.6-13.3) y, patients with CCAs have been found to have higher mortality than those without CCAs (57.5% versus 32.1%; P = 0.007). CCAs are associated with a lower probability of survival also in patients with CMD (P < 0.001) and are independent predictors of mortality (P < 0.001).

Conclusions

Our results demonstrate an interplay between CAV, CMD, and CCAs. We confirm that CAV is associated with CMD, and we show, for the first time, that CMD is associated with CCAs. CCAs are pathophysiologically associated with more severe graft vasculopathy and independently predict mortality after HT.

Latest from the WISE: Contributions to the Understanding of Ischemia and Heart Failure among Women with No Obstructive Coronary Arteries

Since 1996, the National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) has been investigating pathophysiological processes underlying ischemic heart disease in women and related outcomes. Recent findings have focused on women with signs and symptoms of ischemia and no obstructive coronary arteries (INOCA) and their elevated risk for heart failure with preserved ejection fraction (HFpEF). This review summarizes the latest WISE findings related to INOCA and pre-HFpEF characteristics, addressing our understanding of contributions from traditional vs nontraditional risk factors in women.

Application of the Truncated Zero-Inflated Double Poisson for Determining of the Effecting Factors on the Number of Coronary Artery Stenosis

Background

Risk factors of coronary heart disease have been discussed in the literature; however, conventional statistical models are not appropriate when the outcome of interest is number of vessels with obstructive coronary artery disease. In this paper, a novel statistical model is discussed to investigate the risk factors of number of vessels with obstructive coronary artery disease.

Methods

This cross-sectional study was conducted on 633 elderly cardiovascular patients at Ghaem Hospital, Mashhad, Iran from September 2011 to May 2013. Clinical outcome is number of vessels with obstructive coronary artery disease (=0, 1, 2, 3), and predictor variables are baseline demographics and clinical features. A right-truncated zero-inflated double Poisson regression model is performed which can accommodate both underdispersion and excess zeros in the outcome. The goodness-of-fit of the proposed model is compared with conventional regression models.

Results

Out of 633 cardiovascular patients, 327 were male (51.7%). Mean age was ~65 ± 7 years (for individuals with zero, one ,and two coronary artery stenosis) and ~66 ± 7 years (for individuals with three coronary artery stenosis). BMI (0.04 ± 0.01, p = 0.011) and female gender (0.19 ± 0.09, p = 0.032) were significant associated with the count part of the model, and only BMI (−0.47 ± 0.2, p = 0.011) was significantly predictive of logit part of the model. The goodness-of-fit measurements indicate that the proposed model outperforms the conventional regression models.

Conclusion

The proposal regression model shows a better fit compared to the standard regression analysis in modeling number of vessels with obstructive coronary artery disease. Hence, using truncated zero-inflated double Poisson regression model—as an alternative model—is advised to study the risk factors of number of involved vessels of coronary artery stenosis.

Definitions and Epidemiology of Coronary Functional Abnormalities

Coronary functional abnormalities are frequent causes of angina pectoris, particularly in patients with unobstructed coronary arteries. There is a spectrum of endotypes of functional coronary abnormalities with different mechanisms of pathology including enhanced vasoconstriction (i.e. coronary artery spasm) or impaired vasodilatation, such as impaired coronary flow reserve or increased microvascular resistance. These vasomotor abnormalities can affect various compartments of the coronary circulation such as the epicardial conduit arteries and/or the coronary microcirculation. Unequivocal categorisation and nomenclature of the broad spectrum of disease endotypes is crucial both in clinical practice as well as in clinical trials. This article describes the definitions of coronary functional abnormalities with currently accepted cut-off values, as well as diagnostic methods to identify and distinguish endotypes. The authors also provide a summary of contemporary data on the prevalence of the different endotypes of coronary functional abnormalities and their coexistence.

The Pivotal Role of Invasive Functional Assessment in Patients With Myocardial Infarction With Non-Obstructive Coronary Arteries (MINOCA)

Myocardial infarction with non-obstructive coronary arteries (MINOCA) encompasses several pathophysiological mechanisms not yet fully understood. Among the latter, vasomotion abnormalities and coronary microvascular dysfunction (CMD) play a major role for both epidemiological and prognostic reasons. Despite current guidelines do not recommend routine physiological assessment of both epicardial and microvascular coronary compartments within the context of an acute myocardial infarction, several recent evidence support the critical role of a comprehensive invasive functional assessment in order to identify the underlying pathophysiological mechanism and consequently to select an appropriate therapeutic strategy. Unfortunately, optimal medical therapy for these patients is not currently established due to the lack of dedicated trials evaluating clinical outcomes of commonly used medications for secondary prevention in MINOCA patients. For this reason, additional research is warranted to provide personalized treatments for patients affected by this puzzling clinical entity.

Sex Differences in Coronary Function Test Results in Patient With Angina and Nonobstructive Disease

Introduction: Invasive coronary function testing (CFT) has become the recommended diagnostic tool to assess the various endotypes of coronary vasomotor dysfunction in patients with angina and no obstructive coronary artery disease (ANOCA), which has implications for therapy and prognosis. Although the expanding performance of CFT is leading to increased knowledge of coronary vasomotor dysfunction, little is known about sex-related differences in the results of comprehensive CFT.

Methods: We conducted a prospective study of all consecutive patients with ANOCA that underwent clinically indicated CFT in a tertiary interventional from February 2019 to February 2021. CFT consisted of acetylcholine testing to diagnose epicardial or microvascular spasm, and adenosine testing to diagnose CMD. CMD was defined as an index of microvascular resistance (IMR) ≥ 25 and/or coronary flow reserve (CFR) < 2.0.

Results: In total, 228 women and 38 men underwent CFT. No differences in traditional risk factors were seen, but women had a higher prevalence of migraine (45 vs. 14%, p = 0.001). Men more often had a history of percutaneous coronary intervention (12 vs. 49%, p = 0.001). We found no difference in clinical presentation. Coronary vasomotor dysfunction was present in 95% of men and 88% of women (p = 0.25), but males show more often epicardial spasm and less microvascular spasm than women (63 vs. 42% and 29 vs. 40% respectively, p = 0.039). Impaired CFR was more prevalent among females (6 vs 20%, p = 0.033). IMR [median of 23 (15–32) vs. 19 (13–25), p = 0.08] did not differ between the sexes.

Conclusion: Men undergoing CFT show a comparable prevalence of coronary vascular dysfunction as women. However, men have a higher prevalence of epicardial spasm and a lower prevalence of microvascular spasm compared with women. An impaired CFR was more often present in women, with an equally impairment of IMR.

Prevalence and disease features of myocardial ischemia with non-obstructive coronary arteries: Insights from a dynamic CT myocardial perfusion imaging study

BACKGROUND

Ischemia with non-obstructive coronary arteries (INOCA) is not uncommon in clinical practice. However, the incidence and imaging characteristics of INOCA on dynamic CT myocardial perfusion imaging (CT-MPI) remains unclear. We aimed to investigate the prevalence and disease features of INOCA as evaluated by dynamic CT-MPI + coronary CT angiography (CCTA).

METHODS

Patients with suspected chronic coronary syndrome and intermediate-to-high pre-test probability of obstructive CAD (according to updated Diamond and Forrester Chest Pain Prediction Rule) were referred for dynamic CT-MPI + CCTA and retrospectively included. Various parameters, including myocardial blood flow (MBF) and high-risk plaque (HRP) features, were measured. INOCA was diagnosed if patients were revealed to have myocardial ischemia and absence of obstructive stenosis.

RESULTS

314 patients were finally included. 20 patients (6.4%) were observed to have myocardial ischemia without obstructive stenosis. In addition, 138 patients (43.9%) had normal or near normal findings, 101 patients (32.2%) had obstructive stenosis without myocardial ischemia and 55 patients (17.5%) had obstructive stenosis with myocardial ischemia. Compared with patients with normal/near normal findings, patients with INOCA showed a higher prevalence of positive remodeling (40.0% vs. 17.4%, p = 0.04). In patients with obstructive stenosis, the mean age, calcium score and incidence of spotty calcification, positive remodeling as well as HRPs were significantly higher than those in patients with INOCA (p < 0.05 for all).

CONCLUSIONS

The overall prevalence of INOCA was low in patients with suspected chronic coronary syndrome. HRPs were less frequently presented in patients with INOCA, compared with patients having obstructive coronary stenosis.

Invasive Diagnosis of Coronary Functional Disorders Causing Angina Pectoris

Coronary vasomotion disorders represent a frequent cause of angina and/or dyspnoea in patients with non-obstructed coronary arteries. The highly sophisticated interplay of vasodilatation and vasoconstriction can be assessed in an interventional diagnostic procedure. Established parameters characterising adequate vasodilatation are coronary blood flow at rest, and, after drug-induced vasodilation, coronary flow reserve, and microvascular resistance (hyperaemic microvascular resistance, index of microcirculatory resistance). An increased vasoconstrictive potential is diagnosed by provocation testing with acetylcholine or ergonovine. This enables a diagnosis of coronary epicardial and/or microvascular spasm. Ischaemia associated with microvascular spasm can be confirmed by ischaemic ECG changes and the measurement of lactate concentrations in the coronary sinus. Although interventional diagnostic procedures are helpful for determining the mechanism of the angina, which may be the key to successful medical treatment, they are still neither widely accepted nor applied in many medical centres. This article summarises currently well-established invasive methods for the diagnosis of coronary functional disorders causing angina pectoris.