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.

Physiology and functional significance of the coronary microcirculation: An overview of its implications in health and disease.

Ischemic, Coronary Heart Disease (CHD) is a leading cause of morbidity and death worldwide.

Single Nucleotide Polymorphisms in Coronary Microvascular Dysfunction.

Coronary microvascular dysfunction is an underdiagnosed pathologic process that is associated with adverse clinical outcomes. There are data to suggest that coronary microvascular dysfunction, in some cases, may be genetically determined. We present an updated review of single nucleotide polymorphisms in coronary microvascular dysfunction.

Elevated high-density lipoprotein cholesterol and adverse outcomes in women with symptoms of ischemic heart disease.

Background: Emerging data in the general population and those with coronary artery disease demonstrate higher risk of adverse outcomes with high (>70 mg/dL) HDL-C levels. There are limited data on the risk of adverse outcomes in women with suspected ischemic heart disease. Objective: To investigate relationships between high (>70 mg/dL), average (50-70 mg/dL), and low (<50 mg/dL) HDL-C levels with major adverse cardiac events (MACE) (death, myocardial infarction, stroke, and heart failure hospitalization), and all-cause mortality in women referred for coronary angiography for suspected myocardial ischemia. Methods: A total of 607 women enrolled in the Women's Ischemia Syndrome Evaluation (WISE) original cohort (NCT00000554) with available HDL-C values were included in this analysis. Associations between HDL-C level and outcomes were evaluated using both multivariate Cox proportional hazard regression and spline regression analysis. Results: The mean age was 59 ± 12 years, 62 % had 3 or more cardiac risk factors, and 66 (10.9 %) had a high HDL-C. High and low HDL-C were both associated with higher MACE risk compared to average HDL-C after adjusting for demographic and clinical characteristics (HR 1.80, CI 1.03-3.14, p = 0.038; HR 1.63, CI 1.09-2.42, p = 0.016, respectively). Similarly, high, and low HDL-C were associated with higher risk of all-cause mortality (HR 3.64, CI 1.84-7.20, p < 0.001; HR 2.81, CI 1.67-4.71, p < 0.001, respectively). Conclusions: High and low HDL-C levels are both independently associated with higher MACE and all-cause mortality in women with suspected ischemia undergoing coronary angiography.

Comparison of risk profiles of participants in the Women's IschemiA TRial to Reduce events In non-ObstRuctive CAD (WARRIOR) trial, using Coronary Computed Tomography Angiography vs Invasive Coronary Angiography.

OBJECTIVE: To compare baseline characteristics of participants in the Women's IschemiA TRial to Reduce Events In Non-ObstRuctive CAD (WARRIOR) trial by qualification by Coronary Computed Tomography Angiography (CCTA) or Invasive Coronary Angiography (ICA). METHODS: The WARRIOR trial (NCT03417388) is an ongoing multicenter, prospective, randomized, blinded outcome evaluation of intensive medical therapy vs. usual care in women with suspected Ischemia and No Obstructive Coronary Artery Disease (INOCA) identified by either CCTA or ICA on the outcome of major adverse cardiovascular events (MACE). No obstructive coronary artery disease is defined as <50% luminal stenosis and normal coronary arteries is defined as no evidence of atherosclerosis including calcified and non-calcified plaque. Data presented was extracted on May 27, 2020. No clinical outcomes were assessed. RESULTS: An initial sample cohort of 797 women was included. The majority were younger than 65 years, White participants (73.3%), 159 had diabetes (19.9%), and 676 had angina (84.8%) with the remainder having symptoms of suspected ischemic heart disease. Over 50% of randomized participants had normal coronaries without luminal irregularities by ICA or CCTA. Participants randomized to ICA were more likely to have worse baseline clinical risk profiles with older age, higher burden of cardiac risk factors and poor quality of life with disabling angina. CONCLUSIONS: Among this initial sample of women with suspected INOCA randomized in the WARRIOR trial, there is a differential baseline cardiac risk of participants enrolled after CCTA or ICA. However, the majority had no evidence of atherosclerotic plaque or obstructive stenosis, after evaluation by ICA or CCTA. These results suggest that non-invasive evaluation with CCTA is likely to be associated with lower risk of MACE.

Recipe for Heart Health: A Randomized Crossover Trial on Cardiometabolic Effects of Extra Virgin Olive Oil Within a Whole-Food Plant-Based Vegan Diet.

BACKGROUND: Whole-food, plant-based vegan diets, low in oils, and Mediterranean diets, rich in extra virgin olive oil (EVOO), reduce cardiovascular disease risk factors. Optimal quantity of dietary fat, particularly EVOO, is unclear. METHODS AND RESULTS: In a randomized crossover trial with weekly cooking classes, adults with ≥5% cardiovascular disease risk followed a high (4 tablespoons/day) to low (<1 teaspoon/day) or low to high EVOO whole-food, plant-based diet for 4 weeks each, separated by a 1-week washout. The primary outcome was difference in low-density lipoprotein cholesterol (LDL-C) from baseline. Secondary measures were changes in additional cardiometabolic markers. Linear mixed models assessed changes from baseline between phases, with age, sex, and body weight change as covariates. In 40 participants, fat intake comprised 48% and 32% of energy during high and low EVOO phases, respectively. Both diets resulted in comparable reductions in LDL-C, total cholesterol, apolipoprotein B, high-density lipoprotein cholesterol, glucose, and high-sensitivity C-reactive protein (all P<0.05). With diet-sequence interactions for LDL-C, differences were detected between diets by diet order (mean±SEM high to low: Δ-12.7[5.9] mg/dL, P=0.04 versus low to high: Δ+15.8[6.8] mg/dL, P=0.02). Similarly, low to high order led to increased glucose, total cholesterol, and high-density lipoprotein cholesterol (all P<0.05). Over period 1, LDL-C reductions were -25.5(5.1) post-low versus -16.7(4.2) mg/dL post-high EVOO, P=0.162, which diminished over period 2. CONCLUSIONS: Both plant-based diet patterns improved cardiometabolic risk profiles compared with baseline diets, with more pronounced decreases in LDL-C after the low EVOO diet. Addition of EVOO after following a low intake pattern may impede further lipid reductions. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04828447.

Evaluation of coronary microvascular dysfunction using magnetocardiography: A new application to an old technology.

Background: In patients with angina and non-obstructive coronary artery disease (ANOCA), diagnosis of coronary microvascular dysfunction (CMD) remains an unmet need. Magnetocardiography (MCG), is a rest-based, non-invasive scan that can detect weak electrophysiological changes that occur at the early phase of ischemia. Objective: This study assessed the ability of MCG to detect CMD in ANOCA patients as compared to reference standard, invasive coronary flow reserve (CFR). Methods: Patients with ANOCA and invasive coronary physiologic assessment using intracoronary flow measurements with Doppler and thermodilution methods were enrolled. CMD was defined dichotomously as an invasive CFR < 2.0 by Doppler or thermodilution assessment. Noninvasive 36-channel 90-s MCG scan was performed and quantitative assessment of four distinct MCG features was completed. We evaluated the diagnostic performance of 2 or more abnormal MCG features to detect CMD in the overall cohort and performed a subgroup analysis in the subset of patients with Doppler CFR assessment. Results: Among 79 ANOCA patients, 25 were CMD positive and 54 patients were CMD negative by CFR. Using invasive CFR as reference, MCG had an ROC AUC of 0.66 with a sensitivity of 68 % and specificity of 65 % for the detection of CMD. In the subgroup with Doppler CFR assessment, MCG had an ROC AUC of 0.76 with a sensitivity of 75 % and specificity of 77 %. Conclusions: In ANOCA patients, MCG demonstrates the ability to detect CMD using a 90-second non-invasive scan without the need for an intravenous stressor or ionizing radiation. Further investigations are needed to validate an MCG-based diagnostic pathway for CMD.

Endogenous androgens, coronary atheroma and remodeling in women with suspected ischemic heart disease: A report from the Women's Ischemia Syndrome Evaluation (WISE) study.

Background: Women have smaller coronary size than men independent of body surface area. Female to male heart transplantation demonstrates coronary lumen enlargement. Purpose: To investigate relationships between endogenous androgens and coronary luminal size in women with suspected ischemic heart disease (IHD). Methods: We analyzed 69 women with available androgen levels. Results: Group mean age was 54 ± 10 years with 64 % post-menopausal. Lumen cross-sectional area (CSA) and external elastic membrane (EEM) CSA positively correlated with free testosterone (FT) (r = 0.29, p = 0.049; r = 0.29, p = 0.01), respectively, and negatively correlated with SHBG (r = -0.26, p = 0.03; r = -0.29, p = 0.02), respectively. Atheroma CSA positively correlated with FT (r = 0.24. p = 0.05). These correlations became non-significant after adjusting for waist circumference. Conclusions: In women with suspected ischemic heart disease, endogenous androgens, coronary atheroma and luminal size are related, and may be moderated by waist circumference.

Pericardial fat volume is related to endothelial-mediated coronary blood flow in women with suspected coronary microvascular dysfunction. A report from the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) study.

Background: Coronary microvascular dysfunction is prevalent in women with signs and symptoms of ischemia but no obstructive coronary artery disease (CAD) and is associated with an adverse prognosis. Elevated pericardial fat volume predicts adverse cardiac events, but mechanistic pathways of the association are not well understood. Methods: 118 women enrolled in the NHLBI-sponsored Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction study with suspected coronary microvascular dysfunction but no obstructive CAD underwent adenosine stress 1.5 T cardiovascular magnetic resonance imaging (CMR) imaging and invasive coronary reactivity testing. Semi-quantitative myocardial perfusion reserve index (MPR) index was derived from perfusion images. Pericardial fat volume was measured by manually contouring the cardiac margins and adjacent adipose tissue on a single trans-axial HASTE slice at the level of the left main coronary artery origin and indexed to body surface-area. Simple standard deviation analysis obtained for continuous variables and frequency (percent) for categorical variables. The relationships between pericardial fat volume and coronary reactivity testing parameters were examined by correlation and multivariable regression analyses. Results: Women with suspected coronary microvascular dysfunction had a mean age of 55 ± 10 years, body mass index (BMI) of 28 ± 7 kg/m2, 44 % had a history of smoking, 63 % hypertension, 8 % diabetes, and 20 % dyslipidemia. CMR imaging-derived pericardial fat volume and coronary blood flow response to intracoronary acetylcholine (Δ CBF) were negatively correlated (r = -0.32, p = 0.0013). After adjustment for age, number of risk factors, high-density lipoprotein (HDL), and cold pressor diameter response, pericardial fat volume remained a significant predictor of Δ coronary blood flow (p = 0.04). There was no association with other coronary reactivity testing measures or CMRI derived MPR index. Conclusions: Among women with suspected coronary microvascular dysfunction but no obstructive CAD, pericardial fat volume appears to be related in a hypothesized adverse direction to coronary microvascular endothelial function. These results support further work confirming and extending these results to investigate pericardial fat volume as mechanistic pathway and potential treatment target for coronary microvascular dysfunction-related adverse events.Trial registration: clinicaltrials.govNCT00832702.

Impact of epicardial fat on coronary vascular function, cardiac morphology, and cardiac function in women with suspected INOCA.

INTRODUCTION: Epicardial fat is a metabolically active adipose tissue depot situated between the myocardium and visceral pericardium that covers ∼80% of the heart surface. While epicardial fat has been associated with the development of atherosclerotic coronary artery disease (CAD), less is known about the relationship between epicardial fat and coronary vascular function. Moreover, the relations between excess epicardial fat and cardiac morphology and function remains incompletely understood. METHODS AND RESULTS: To address these knowledge gaps, we retrospectively analyzed data from 294 individuals from our database of women with suspected ischemia with no obstructive coronary disease (INOCA) who underwent both invasive coronary function testing and cardiac magnetic resonance imaging (cMRI). Epicardial fat area, biventricular morphology, and function, as well as left atrial function, were assessed from cine images, per established protocols. The major novel findings were twofold: First, epicardial fat area was not associated with coronary vascular dysfunction. Second, epicardial fat was associated with increased left ventricular concentricity (ß= 0.15, p= 0.01), increased septal thickness (ß= 0.17, p= 0.002), and reduced left atrial conduit fraction (ß= -0.15, p= 0.02), even after accounting for age, BMI, and history of hypertension. CONCLUSIONS: Taken together, these data do not support a measurable relationship between epicardial fat and coronary vascular dysfunction but does suggest that epicardial fat may be related to concentric remodeling and diastolic dysfunction in women with suspected INOCA. Prospective studies are needed to elucidate the long-term impact of epicardial fat in this patient population.

Angiogenic Gene Therapy for Refractory Angina: Results of the EXACT Phase 2 Trial.

BACKGROUND: XC001 is a novel adenoviral-5 vector designed to express multiple isoforms of VEGF (vascular endothelial growth factor) and more safely and potently induce angiogenesis. The EXACT trial (Epicardial Delivery of XC001 Gene Therapy for Refractory Angina Coronary Treatment) assessed the safety and preliminary efficacy of XC001 in patients with no option refractory angina. METHODS: In this single-arm, multicenter, open-label trial, 32 patients with no option refractory angina received a single treatment of XC001 (1×1011 viral particles) via transepicardial delivery. RESULTS: There were no severe adverse events attributed to the study drug. Twenty expected severe adverse events in 13 patients were related to the surgical procedure. Total exercise duration increased from a mean±SD of 359.9±105.55 seconds at baseline to 448.2±168.45 (3 months), 449.2±175.9 (6 months), and 477.6±174.7 (12 months; +88.3 [95% CI, 37.1-139.5], +84.5 [95% CI, 34.1-134.9], and +115.5 [95% CI, 59.1-171.9]). Total myocardial perfusion deficit on positron emission tomography imaging decreased by 10.2% (95% CI, -3.1% to 23.5%), 14.3% (95% CI, 2.8%-25.7%), and 10.2% (95% CI, -0.8% to -21.2%). Angina frequency decreased from a mean±SD 12.2±12.5 episodes to 5.2±7.2 (3 months), 5.1±7.8 (6 months), and 2.7±4.8 (12 months), with an average decrease of 7.7 (95% CI, 4.1-11.3), 6.6 (95% CI, 3.5-9.7), and 8.8 (4.6-13.0) episodes at 3, 6, and 12 months. Angina class improved in 81% of participants at 6 months. CONCLUSIONS: XC001 administered via transepicardial delivery is safe and generally well tolerated. Exploratory improvements in total exercise duration, ischemic burden, and subjective measures support a biologic effect sustained to 12 months, warranting further investigation. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04125732.

Reprograming of transcriptional profile of colonic organoids from patients with high blood pressure by minocycline.

Minocycline, an anti-inflammatory antibiotic drug, rebalances impaired gut microbiota, attenuates neuroinflammation and lowers high blood pressure in animal models of hypertension and in hypertensive patients. Our objective in this study was to investigate if antihypertensive effects of minocycline involve the expression of gut epithelial genes relevant to blood pressure homeostasis using human colonic 3-dimensional organoid culture and high-throughput RNA sequencing. The data demonstrates that minocycline could restore impaired expression of functional genes linked to viral and bacterial immunity, inflammation, protein trafficking and autophagy in human hypertensive organoids.

Relationship between arm span to height ratio, aortic root diameter, and systolic blood pressure in collegiate athletes.

Study objective: Sudden cardiac death is the most common cause of non-traumatic death in collegiate athletes. Marfan syndrome poses a risk for sudden cardiac death secondary to aortic root dilation leading to aortic dissection or rupture. Arm span to height ratio (ASHR) > 1.05 has been proposed as a screening tool for Marfan syndrome in pre-participation examinations (PPE) for collegiate athletes but limited data exists on the association between ASHR and aortic root diameter (ARD). This study examines the relationship between ASHR and ARD and assesses for predictors of ARD. Design: Retrospective chart review. Setting: National Collegiate Athletic Association Division I University. Participants: 793 athletes across thirteen sports between 2012 and 2022 evaluated with PPE and screening echocardiogram. Interventions: Not applicable. Main outcome measures: (1) Relationships between ASHR, SBP, BSA, and ARD amongst all athletes as well as stratified by ASHR >1.05 or ≤1.05 using univariate analysis. (2) Predictors of ARD using multivariate analysis using linear regression. Results: 143 athletes (18 %) had ASHRs > 1.05. Athletes with ASHR > 1.05 had higher ARD (2.99 cm) than athletes with ASHR ≤ 1.05 (2.85 cm). Weak correlations were noted between ASHR, ARD, and SBP. Multivariate analysis showed that BSA, male sex, and participation in swimming were predictors of ARD. ASHR was not predictive of ARD in regression analysis. Conclusions: These findings showed a tendency towards higher ARD in athletes with ASHR >1.05 but this observation was not statistically significant in multivariate analysis.

Chronic rheumatologic disorders and cardiovascular disease risk in women.

Cardiovascular disease (CVD) is a major health threat to women worldwide. In addition to traditional CVD risk factors, autoimmune conditions are increasingly being recognized as contributors to adverse CVD consequences in women. Chronic systemic autoimmune and inflammatory disorders can trigger premature and accelerated atherosclerosis, microvascular dysfunction, and thrombosis. The presence of comorbid conditions, duration of the autoimmune condition, disease severity, and treatment of underlying inflammation are all factors that impact CVD risk and progression. Early identification and screening of CVD risk factors in those with underlying autoimmune conditions may attenuate CVD in this population. Treatment with non-steroidal anti-inflammatory drugs, corticosteroids, disease modifying agents and biologics may influence CVD risk factors and overall risk. Multi-disciplinary and team-based care, clinical trials, and collaborative team-science studies focusing on systemic autoimmune conditions will be beneficial to advance care for women.

Dietary Composition, Angiographic Coronary Disease, and Cardiovascular Outcomes in the WISE Study (Women's Ischemia Syndrome Evaluation).

BACKGROUND: Studies relating diet to angiographic coronary artery disease (CAD) and subsequent major adverse cardiac events (MACE) in women are limited. Information on diet was collected in the Women's Ischemia Syndrome Evaluation (WISE), a prospective cohort study of symptomatic women referred for coronary angiography to evaluate suspected ischemic heart disease. METHODS: A consecutive subgroup (n = 201 of 936) of enrolled women completed the modified Block food frequency questionnaire (FFQ). Data on outcomes were collected and adjudicated after 8-year follow-up. A set of logistic regression models were fitted for non-obstructive versus obstructive coronary stenosis (<50% versus ≥50%). Cox proportional hazard regression models were fitted for outcomes, with each dietary composition variable adjusted for the degree of coronary stenosis. RESULTS: At baseline, the subgroup cohort was 58 ± 12 years old with a body mass index (BMI) of 30 ± 7 kg/m2. An increased proportion of calories consumed from protein was associated with higher levels of baseline obstructive coronary stenosis. Those individuals who ate a higher amount of protein, carotene, and servings of vegetables and meat, however, were each associated with lower subsequent adverse outcomes, respectively. CONCLUSIONS: Among women undergoing coronary angiography for suspected CAD, a higher percentage of protein intake was associated with higher baseline stenosis severity; however, the amount of protein intake, vegetable, meat, and carotene intake, was conversely associated with subsequent lower adverse cardiovascular outcome risk.

Association of abnormal electrocardiography response on dobutamine stress echocardiogram with longer-term major adverse cardiovascular events in women with symptoms of ischemic heart disease.

Background: Prior work demonstrates patients with positive (+) electrocardiogram (ECG) but negative (-) echocardiogram wall motion abnormalities (WMAs) on dobutamine stress echocardiography (DSE) testing have an elevated of major adverse cardiovascular events (MACEs). In this study, we aimed to evaluate the long-term prognosis of women with suspected ischemia with no obstructive coronary artery (INOCA) disease by utilizing core lab read DSE, specifically focusing on those with + ECG findings. Methods: Among women with signs and symptoms of myocardial ischemia undergoing clinically indicated coronary angiography enrolled in the Women's Ischemia Syndrome Evaluation (WISE) [1997-2001], a prospective cohort study, 99 underwent standardized DSE by site design. Women with positive DSE (n=17), defined as an increase in score based on wall motion scoring index were excluded except for akinetic to dyskinetic (n=10), providing 82 patients in this analysis. ECG was assessed by core laboratory and (+) ECG was defined as >1 mm ST change. Non-obstructive coronary artery disease (CAD) was assessed by core laboratory quantitative coronary angiography and defined as <50% epicardial stenosis. All-cause death follow-up was an average of 8 years, while adjudicated MACE [all-cause mortality, nonfatal myocardial infarction (MI), nonfatal stroke, heart failure hospitalization] was an average of 5.5 years. Comparisons among subject groups [i.e., (+) ECG and (-) ECG] were made using chi-square or Fisher's exact tests for categorical variables and t-test or Wilcoxon rank-sum test for continuous variables. Results: Demographic profile included a mean age 59±10 years; 55% had hypertension (HTN), 29% diabetes mellitus (DM), and 72% non-obstructive CAD. Overall, 9/82 women (11%) had (+) ECG in the absence of WMAs. There were significant differences in family history of CAD (P=0.009) and vasodilator (P=0.042) use between the (+) ECG and (-) ECG groups, but otherwise had no significant demographic or clinical differences. At longer-term follow up, patients with (+) ECG had higher risk of MACE [unadjusted hazard ratio (HR): 4.91, 95% confidence interval (CI): 1.83, 13.19, P=0.002]. Conclusions: Abnormal stress ECG findings on dobutamine stress testing with a negative DSE should be viewed as an indicator of longer-term risk in women with signs and symptoms of ischemia.

Intravenous administration of umbilical cord lining stem cells in left ventricular assist device recipient: Rationale and design of the uSTOP LVAD BLEED pilot study.

Background: Left ventricular assist device (LVAD) implantation provides a robust survival advantage, however despite improvements in mortality, the adverse event burden of durable mechanical circulatory support remains high. Bleeding complications are one such significant complication. The uSTOP LVAD BLEED (Utilization of umbilical cord lining Stem cells TO Prevent LVAD associated angiodysplastic BLEEDing) pilot study is designed to evaluate the safety and tolerability of escalating doses of umbilical cord lining stem cells (ULSCs) in LVAD recipients to ameliorate the dysregulation of angiogenic factors seen in this population. Design: This Phase Ia single-ascending dose pilot study will evaluate the IV administration of ULSCs in stable out-patients supported with an LVAD. In a 3 + 3 design, a maximum of 18 patients will receive an IV infusion of ULSCs. Main outcome measures: The primary endpoints are safety and tolerability, secondary exploratory endpoints will include biomarker evaluation of angiogenic dysregulation. Summary: This represents a novel cell type and route of administration in this population, while collecting initial data regarding the magnitude and duration of effects of cell therapy, and assessing the possibility of decreasing bleeding by a strategy of vascular stabilization. Clinical trial registration: ClinicalTrials.gov Identifier: NCT04811261. https://clinicaltrials.gov/ct2/show/NCT04811261.

Dare to dream? Cell-based therapies for heart failure after DREAM-HF: Review and roadmap for future clinical study.

Clinical trials of cell-based therapies for heart failure have resulted in significant strides forward in our understanding of the potential the failing heart has for regeneration and repair. Yet, two decades on, the need for novel cell-based therapies for heart failure has never been greater. The DREAM-HF trial, which was presented as a late-breaking trial at the American Heart Association Scientific Sessions 2021 did not meet the primary heart failure outcome, but did show a large, clinically significant reduction in major adverse cardiovascular events (MACE) in patients receiving cells, an effect that was most pronounced in patients with evidence of maladaptive inflammation. These results represent an important step forward in our understanding of how cell-based therapies can exert beneficial effects in patients with heart failure and should serve as a guide for future clinical efforts. In light of the results of DREAM-HF, this review serves to provide an understanding of the current state of cell-based therapies for heart failure, as well as to highlight major knowledge gaps and suggest guiding principles for clinical trials of cell therapy going forward. Using the knowledge gained from DREAM-HF along with the trials that preceded it, the potential for breakthrough cell-based therapies for heart failure in the coming decade is immense.

Coronary microvascular dysfunction as a chronic inflammatory state: Is there a role for omega-3 fatty acid treatment?

Coronary microvascular dysfunction is a ubiquitous pathologic process that is operational in ischemia with no obstructive coronary artery disease and other cardiovascular disorders including heart failure with preserved ejection fraction. It may, in fact, be a manifestation of a multi-systemic condition of small vessel dysfunction that also affects the brain and kidneys. While the pathophysiology driving coronary microvascular dysfunction is multifactorial, chronic inflammation plays an important role. Resolution of inflammation is an active process mediated, in part, by a family of locally active mediators biosynthesized from omega-3 fatty acids, collectively referred to as specialized pro-resolving mediators. Omega-3 fatty acid treatment modulates inflammation and is associated with improved cardiovascular outcomes and attenuation of plaque progression on cardiovascular imaging. Whether omega-3 fatty acid treatment attenuates coronary microvascular dysfunction is unknown.

Critical role of the coronary microvasculature in heart disease: From pathologic driving force to "innocent" bystander.

The coronary microvasculature is responsible for providing oxygen and nutrients to myocardial tissue. A healthy microvasculature with an intact and properly functioning endothelium accomplishes this by seemless changes in vascular tone to match supply and demand. Perturbations in the normal physiology of the microvasculature, including endothelial and/or vascular smooth muscle dysfunction, result in impaired function (vasoconstriction, antithrombotic, etc.) and structural (hypertrophic, fibrotic) abnormalities that lead to microvascular ischemia and potential organ damage. While coronary microvascular dysfunction (CMD) is the primary pathologic driving force in ischemia with non-obstructive coronary artery disease (INOCA), angina with no obstructive coronary arteries (ANOCA), and myocardial infarction with non-obstructed coronary arteries (MINOCA), it may be a bystander in many cardiac disorders which later become pathologically associated with signs and/or symptoms of myocardial ischemia. Importantly, regardless of the primary or secondary basis of CMD in the heart, it is associated with important increases in morbidity and mortality. In this review we discuss salient features pertaining to known pathophysiologic mechanisms driving CMD, the spectrum of heart diseases where it places a critical role, invasive and non-invasive diagnostic testing, management strategies, and the gaps in knowledge where future research efforts are needed.