Typical angina is associated with greater coronary endothelial dysfunction but not abnormal vasodilatory reserve

Coronary endothelial dysfunction: from pathogenesis to clinical implications

Endothelial dysfunction (ED) has a substantial role in the pathogenesis of atherosclerosis and other vascular diseases. Multiple risk factors, including smoking, hyperlipiadaemia and diabetes, can have associated ED, which is correlated with cardiac events. Measurement of coronary artery endothelial function requires the use of invasive techniques to assess both epicardial coronary artery and microvascular beds. Peripheral vascular techniques and endothelial biomarkers can be used to indirectly assess coronary ED. In this review of coronary artery ED, we discuss the current state of the field, the techniques used to measure ED and its clinical implications.

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

BACKGROUND

Women with suspected ischemia and no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD) as measured by impaired coronary flow reserve (CFR), which is associated with angina and adverse cardiovascular events. CFR is a ratio of hyperemic to baseline average peak velocity (bAPV), and the relation of baseline flow to angina is not understood.

METHODS

We evaluated 259 women enrolled in the WISE-Coronary Vascular Dysfunction (WISE-CVD) project with suspected CMD who underwent invasive coronary functional testing. We analyzed variables stratified by high (e.g. ≥22 cm/s) vs low (<22 cm/s) bAPV, using t-test or Wilcoxon rank; linear and multivariable regression was used with bAPV as a continuous variable.

RESULTS

Women with high bAPV had worse Seattle Angina Questionnaire (SAQ) angina frequency (58 ± 26 vs 67 ± 25, p = 0.005) and SAQ-7 scores (57 ± 22 vs 62 ± 21, p = 0.03), with higher nitrate (p = 0.02) and ranolazine use (p = 0.03). The high bAPV subgroup also had lower CFR (p < 0.001)). Linear regression related higher bAPV with lower SAQ-7 (p = 0.01) and lower angina frequency scores (p = 0.001). These results remained significant in multivariable modelling adjusting for baseline differences (p < 0.04). SAQ-7 was significantly predicted by bAPV.

CONCLUSIONS

Among women with suspected INOCA, angina relates to high bAPV, a result supported by the concomitant greater use of anti-anginal drugs. These results suggest that high bAPV contributes to impaired CFR and may represent a specific pathophysiologic contributor to CMD and may be a treatment target in INOCA subjects.

Evaluation of non-invasive imaging parameters in coronary microvascular disease: a systematic review

BACKGROUND

Coronary microvascular dysfunction (CMD) is an important underlying cause of angina pectoris. Currently, no diagnostic tool is available to directly visualize the coronary microvasculature. Invasive microvascular reactivity testing is the diagnostic standard for CMD, but several non-invasive imaging techniques are being evaluated. However, evidence on reported non-invasive parameters and cut-off values is limited. Thus, we aimed to provide an overview of reported non-invasive parameters and corresponding cut-off values for CMD.

METHODS

Pubmed and EMBASE databases were systematically searched for studies enrolling patients with angina pectoris without obstructed coronary arteries, investigating at least one non-invasive imaging technique to quantify CMD. Methodological quality assessment of included studies was performed using QUADAS-2.

RESULTS

Thirty-seven studies were included. Ten cardiac magnetic resonance studies reported MPRI and nine positron emission tomography (PET) and transthoracic echocardiography (TTE) studies reported CFR. Mean MPRI ranged from 1.47 ± 0.36 to 2.01 ± 0.41 in patients and from 1.50 ± 0.47 to 2.68 ± 0.49 in controls without CMD. Reported mean CFR in PET and TTE ranged from 1.39 ± 0.31 to 2.85 ± 1.35 and 1.69 ± 0.40 to 2.40 ± 0.40 for patients, and 2.68 ± 0.83 to 4.32 ± 1.78 and 2.65 ± 0.65 to 3.31 ± 1.10 for controls, respectively.

CONCLUSIONS

This systematic review summarized current evidence on reported parameters and cut-off values to diagnose CMD for various non-invasive imaging modalities. In current clinical practice, CMD is generally diagnosed with a CFR less than 2.0. However, due to heterogeneity in methodology and reporting of outcome measures, outcomes could not be compared and no definite reference values could be provided.

Prognostic Value of Pre-Infarction Angina Combined with Mean Platelet Volume to Lymphocyte Count Ratio for No-Reflow and Short-Term Mortality in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention

Background

The aim of the present study was to investigate the clinical predictive value of pre-infarction angina (PIA) combined with mean platelet volume to lymphocyte count ratio (MPVLR) for no-reflow phenomenon and short-term mortality in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI).

Material/Methods

A total of 1009 STEMI patients who had undergone PCI were enrolled and subdivided into 4 groups based on the occurrence of PIA and the presence of MPVLR above or below the cutoff value. Analysis of the predictors of the no-reflow phenomenon and 90-day mortality was conducted. Further, evaluation and comparison of the clinical predictive value of PIA, MPVLR, and their combination were done.

Results

Both MPVLR (odds ratio [OR]=1.476, 95% confidence interval [CI]: 1.401 to 1.756, P<0.001; hazard ratio [HR]=1.430, 95% CI: 1.287 to 1.643, P<0.001) and PIA (OR=0.905, 95% CI: 0.783 to 0.986, P<0.001; HR=0.878, 95% CI: 0.796 to 0.948, P<0.001) were independent predictors of no-reflow phenomenon and 90-day mortality. Spearman’s rank correlation test revealed that MPVLR (r=−0.297, P<0.001), monocyte to lymphocyte count ratio (MLR) (r=−0.211, P<0.001) and neutrophil to lymphocyte count ratio (NLR) (r=−0.389, P<0.001) in peripheral blood were significantly negatively correlated with postoperative left ventricular ejection fraction (LVEF). Upon comparing the area under curve (AUC), the MPVLR combined with PIA achieved better performance in differentiating no-reflow phenomenon (AUC=0.847, 95% CI: 0.821 to 0.874) and 90-day mortality (AUC=0.790, 95% CI: 0.725 to 0.855), than the GRACE score, MPVLR and PIA alone, and had similar performance to all other pairwise combinations of the GRACE score, MPVLR and PIA.

Conclusions

High MPVLR and PIA were independent predictors of the no-reflow phenomenon and 90-day mortality in patients with STEMI after PCI. Moreover, Combined application of MPVLR and PIA can effectively predict the occurrence of the no-reflow phenomenon and 90-day mortality.

Typical angina is associated with greater coronary endothelial dysfunction but not abnormal vasodilatory reserve

Background

Typical angina (TA) is defined as substernal chest pain precipitated by physical exertion or emotional stress and relieved with rest or nitroglycerin. Women and elderly patients are usually have atypical symptoms both at rest and during stress, often in the setting of nonobstructive coronary artery disease (CAD).

Hypothesis

To further understand this, we performed subgroup analysis comparing subjects who presented with TA vs nontypical angina (NTA) using baseline data of patients with nonobstructive CAD and coronary microvascular dysfunction (CMD) enrolled in a clinical trial.

Methods

155 subjects from the RWISE study were divided into 2 groups based on angina characteristics: TA (defined as above) and NTA (angina that does not meet criteria for TA). Coronary reactivity testing (responses to adenosine, acetylcholine, and nitroglycerin), cardiac magnetic resonance–determined myocardial perfusion reserve index (MPRI), baseline Seattle Angina Questionnaire (SAQ), and Duke Activity Status Index (DASI) scores were evaluated.

Results

The mean age was 55 ± 10 years; Overall, 30% of subjects had TA. Baseline shortness of breath, invasively assessed acetylcholine‐mediated coronary endothelial function, and SAQ score were worse in the TA group (all P < 0.05), whereas adenosine‐mediated coronary flow reserve, MPRI, and DASI score were similar to the NTA group.

Conclusions

Among subjects with CMD and no obstructive CAD, those with TA had more angina pectoris, shortness of breath, and worse quality of life, as well as more severe coronary endothelial dysfunction. Typical angina in the setting of CMD is associated with worse symptom burden and coronary endothelial dysfunction. These results indicate that TA CMD subjects represent a relatively new CAD phenotype for future study and treatment trials.