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BACKGROUND: Myocardial infarction with nonobstructive coronary arteries (MINOCAs) and angina with nonobstructive coronary arteries (ANOCAs) present diagnostic and therapeutic challenges. We assessed the frequency of coronary microvascular disease (CMD) and its subtypes in MINOCA compared with ANOCA and evaluated long-term cardiovascular outcomes. METHODS: Patients with nonobstructive coronary arteries undergoing invasive coronary function testing from 2012 to 2022 were prospectively enrolled and retrospectively classified as MINOCA or ANOCA (reference group). Myocardial infarction due to atherothrombosis, myocarditis, and Takotsubo syndrome were excluded. Invasive provocation testing was performed. CMD was classified as endothelium-independent (coronary flow reserve <2.5 with adenosine) and endothelium-dependent (<50% increase in coronary blood flow with acetylcholine). Major adverse cardiovascular events (cardiac death, nonfatal myocardial infarction, heart failure hospitalization, urgent revascularization, stroke) were recorded over 8 years. RESULTS: Of 622 patients, 73 (12%) had MINOCA (69% female, median age 56 years) and 549 (88%) ANOCA (72% female, median age 53 years). CMD was common in both groups (71% versus 64%; P =0.271), while endothelium-independent CMD was more frequent in MINOCA (41% versus 21%; P <0.001). Over a median follow-up of 4.5 years, major adverse cardiovascular events occurred more often in MINOCA (40% versus 11%; adjusted hazard ratio, 2.4; P =0.001). CMD predicted higher major adverse cardiovascular events in both MINOCA (hazard ratio, 3.6 [95% CI, 1.1–12.0]; P =0.038) and ANOCA (hazard ratio, 7.9 [95% CI, 2.9–21.8]; P <0.001). CONCLUSIONS: CMD is common in both MINOCA and ANOCA. The higher prevalence of endothelium-independent CMD in MINOCA suggests a potential mechanistic role in infarction. Patients with MINOCA have a worse prognosis than ANOCA, particularly when CMD is present.

Abstract Background Coronary flow augmentation occurs through the simultaneous interaction and regulation of both endothelium-dependent and endothelium-independent mechanisms. A decrease in coronary flow reserve (CFR) secondary to either mechanism is associated with poor prognosis. However, at the individual level, the integrated impact of these two mechanisms has not been thoroughly investigated. Purpose This study investigated the prognostic implications of an integrated metric, CFRsum, combining endothelium-dependent and -independent CFR. Methods A total of 1441 patients with angina with non-obstructive coronary artery (ANOCA) undergoing coronary reactivity testing were studied. Endothelium-independent CFR was measured during adenosine-induced hyperemia, and endothelium-dependent CFR during intracoronary acetylcholine infusion. CFRsum was calculated by summing these components. Cardiovascular event was defined as composite of cardiovascular death, myocardial infarction, heart failure, and cerebral infarction. Results Our patients had a median age of 51.7 years, 69.0% of whom were female, and their CFRsum was 4.57 [3.88, 5.37]. Patients were divided into three tertile-based groups, and Cox proportional hazards analysis demonstrated that all CFR classes were independent predictors of prognosis, with CFRsum providing the best model fit (Likelihood ratio: 54.62, degrees of freedom: 7, P &lt; 0.001). The Kaplan-Meier curve (Figure) demonstrated a stepwise deterioration in prognosis across CFRsum tertile groups, with lower CFRsum being associated with progressively worse outcomes (p &lt; 0.001). Stratification by follow-up duration (3 years) revealed that patients with middle-range CFRsum exhibited comparable outcomes to those with the highest CFRsum during the early phase (&lt;3y) but significantly worse outcomes in the late phase (≥3y) (P = 0.459 and P &lt; 0.001, respectively). Conclusion CFRsum showed superior prognostic value over traditional CFR metrics in patients with ANOCA, identifying a compensated group with time-varying outcomes. This novel metric improves the assessment of microvascular function and supports better clinical management.

Introduction: Intracranial atherosclerosis (ICAS) is a leading cause of ischemic stroke (IS) worldwide and carries a high risk of recurrence. Current guidelines favor 90 days of dual antiplatelet therapy (DAPT) for severe symptomatic ICAS, but recurrence remain high. Limited data suggest possible benefit of single antiplatelet plus anticoagulation (SAPT+AC). We compared the effectiveness and safety of DAPT versus SAPT+AC. We hypothesized that DAPT would lower 90-day recurrent IS risk without significantly increasing bleeding. Methods: This substudy of the Biomarkers and Recurrence Risk in Symptomatic Intracranial Arterial Stenosis (BIORISK-ICAS) included patients from 35 centers (Jan 2019–Jun 2024) with symptomatic 50–99% ICAS in the intracranial internal carotid, vertebral, basilar, or M1 segment of the MCA, presenting ≤72 hours from last known well. The primary efficacy outcome was recurrent IS in the same vascular territory at 90 days; the primary safety outcome was severe bleeding (symptomatic intracranial hemorrhage or major extracranial bleeding). Categorical variables were compared using χ 2 and continuous variables with the Student's t test; multivariable Cox regression adjusted for key covariates. Results: Of 2050 BIORISK-ICAS patients, 1658 met criteria (DAPT n=1499; SAPT+AC n=159). Mean age was 67 vs. 73 years, and 44% were women. At 90 days, recurrent IS occurred in 121 DAPT patients (8.07%) vs. 13 SAPT+AC patients (8.17%); unadjusted HR 0.83 (95% CI, 0.50–1.36; p=0.46). After adjustment for age, diabetes, coronary heart disease, atrial fibrillation, active smoking, and borderzone infarct, the adjusted HR was 0.99 (95% CI, 0.52–1.86; p=0.97). Severe bleeding occurred in 34 DAPT patients (2.26%) and 5 SAPT+AC patients (3.14%); unadjusted HR 0.79 (95% CI, 0.28–1.85; p=0.50), adjusted HR 0.66 (95% CI, 0.21–2.09; p=0.47). Conclusions: In patients with symptomatic ICAS, DAPT and SAPT+AC were associated with similar risks of 90-day recurrent ischemic stroke and severe bleeding. Well-powered randomized trials are needed to determine the optimal antithrombotic regimen in this high-risk population.

Background: Coronary microvascular dysfunction (CMD) is a common cause of angina with non-obstructive coronary arteries (ANOCA), but its role in patients with a history of myocardial infarction with non-obstructive coronary arteries (MINOCA) is much less understood. We investigated the incidence of major adverse cardiac and cerebrovascular events (MACCE) in patients undergoing invasive assessment for CMD, divided into patients with MINOCA versus patients with ANOCA. We hypothesized that CMD would be common in both groups. Methods: Serial patients undergoing invasive coronary provocation testing between 2012 and 2022 were divided into MINOCA (n=76) or ANOCA (n=561). Doppler study was performed in the left anterior descending artery. CMD was defined as either coronary flow reserve (CFR) <2.5 with adenosine or <50% increase in flow with acetylcholine. Patients were followed prospectively through 2025. Incidence of MACCE (cardiac death, non-fatal MI, hospitalization for heart failure, urgent revascularization, and stroke) was compared between MINOCA and ANOCA and further analyzed by CMD status. Kaplan-Meier curves were constructed and Cox proportional hazards models were used to estimate hazard ratios (HRs). Results: Among patients with MINOCA, 53 of 76 (70%) had CMD, compared to 363 of 561 (65%) with ANOCA. Invasive provocation testing was performed a median of 163 days (IQR 13 – 255 days) after the MI in the MINOCA group. Patients were then followed for a median of 4.4 years (IQR 3.0 – 6.9 years). MACCE-free survival was significantly lower in patients with MINOCA compared to those with ANOCA (HR = 3.57, p < 0.001; Figure 1). The major contributor to MACCE was non-fatal MI in MINOCA (24%) and heart failure hospitalization in ANOCA (6%). The presence of CMD was associated with worse prognosis in both MINOCA (HR = 3.76, p = 0.02) and ANOCA (HR = 8.35, p < 0.001; Figure 2). Conclusions: Patients with MINOCA experience significantly higher long-term risk of major adverse events compared to those with ANOCA. CMD is common in both groups and is independently associated with worse outcomes. Specifically, patients with CMD had higher rates of MACCE over time, regardless of whether they presented with MINOCA or ANOCA. Invasive assessment of CMD in patients with myocardial infarction and non-obstructive coronary arteries may improve risk stratification and inform management strategies in these understudied populations

Background: Coronary microvascular disease (CMD) may be endothelium-independent (coronary flow reserve, CFR < 2.5) or endothelium-dependent (<50% increase in coronary blood flow in response to acetylcholine). CMD has been implicated in abnormal myocardial relaxation and impaired diastolic function. Wave intensity analysis (WIA) is a hemodynamic method that quantifies the energy of pressure-flow waves driving coronary blood flow. The backward expansion wave (BEW) is the dominant distally originating wave, generated by microvascular suction during ventricular relaxation. Thus, the BEW may offer mechanistic insight into the link between CMD and diastolic dysfunction. Hypothesis: We hypothesized that diastolic dysfunction would be more common in patients with CMD, and that the backward expansion wave (BEW) intensity would be lower in those with diastolic dysfunction compared to those without. Methods: Patients with non-obstructive coronary artery disease undergoing invasive coronary physiology assessment of the left anterior descending artery were included (n = 113). Pressure and Doppler flow were recorded at rest, with adenosine, and with acetylcholine for categorization of CMD as endothelium-independent (CMD-Ei) and/or endothelium-dependent (CMD-Ed). Wave intensity analysis was used to calculate cumulative BEW (J×m -2 ) at rest in CMD, CMD-Ei (endothelium-independent), and CMD-Ed (endothelium-dependent) subgroups. Diastolic dysfunction was diagnosed by transthoracic echocardiogram using the 2016 American Society of Echocardiography (ASE) guidelines. Results: Of the 113 study patients, 88 (77.9%) had CMD and 25 (22.1%) did not. Among those with CMD, 39 patients (44.3%) had diastolic dysfunction (Figure 1). In the patients with CMD, the BEW intensity was significantly lower in patients with diastolic dysfunction compared to those without (6.5 vs. 9.0 × 10 3 W×m -2 ×s -1 , p < 0.05). The same trend was observed for the CMD-Ei (7.2 vs. 9.7 × 10 3 W×m -2 ×s -1 , p < 0.05) and CMD-Ed (6.2 vs. 9.1 × 10 3 W×m -2 ×s -1 , p < 0.05) subtypes. Conclusions: Diastolic dysfunction is frequent in patients with invasively diagnosed CMD. Patients with CMD who have diastolic dysfunction have comparatively lower BEW intensity, regardless of endothelial subtype. Since the BEW is the major driver of coronary flow during diastole, this suggests a mechanism by which CMD may lead to diastolic dysfunction.

Background: Coronary wave intensity analysis (WIA) provides a mechanistic view of coronary hemodynamics and has been increasingly used to phenotype coronary microvascular disease (CMD). Standard WIA requires simultaneous pressure and flow measurements within the same vessel, but intra-coronary pressure measurement may be limited by hardware availability. In patients with non-obstructive coronary arteries, aortic pressure may serve as a surrogate for intra-coronary pressure to enable broader feasibility of WIA. We aimed to determine whether wave profiles derived from intra-aortic and intra-coronary pressure measurements are comparable when paired with intracoronary Doppler flow in patients with non-obstructive coronary artery disease. Methods: Patients undergoing invasive coronary physiology assessment of the left anterior descending artery were included. Intracoronary flow velocity and intra-coronary pressure were simultaneously recorded using a ComboWire (Philips Volcano) in the proximal LAD. Aortic pressure was concurrently measured via the guide catheter to allow comparison of pressure sources. In the intra-aortic pressure group, pressure and flow data were aligned using the R wave of the ECG trace. WIA was performed using conventional methods to quantify the dominant waves: forward compression wave (FCW), backward compression wave (BCW), and backward expansion wave (BEW). Agreement between wave intensity was assessed using Bland-Altman analysis and Pearson correlation. Results: A total of 14 paired waveforms were analyzed with a total of 42 coronary waves compared. Wave intensities calculated using intra-coronary versus intra-aortic pressure showed excellent agreement across all wave types. Mean bias between methods was −0.07 x 10 3 W×m -2 ×s -1 with limits of agreement from −0.63 to +0.49. The correlation between intra-coronary and intra-aortic wave intensities was strong (r = 0.997, p < 0.001), with minimal dispersion and consistent agreement across the full range of wave intensities ( Figure 1 ). Conclusions: In patients with non-obstructive coronary arteries, wave intensity analysis using guide-catheter aortic pressure yields results nearly identical to those obtained with intra-coronary pressure. These findings support the use of aortic pressure as a reliable surrogate for intra-coronary pressure in WIA for the calculation of microvascular coronary hemodynamics, reducing technical barriers and enabling broader clinical and research utilization.

BACKGROUND: Intracranial atherosclerosis (ICAS) is associated with an increased risk of early recurrent ischemic stroke. We evaluated whether biomarkers of impaired distal perfusion—specifically, anterior circulation borderzone infarct, and hypoperfusion mismatch volume—were associated with recurrent ischemic stroke within 90 days. METHODS: The BIORISK ICAS (Biomarkers and Recurrence Risk in Symptomatic Intracranial Atherosclerosis) is a multicenter retrospective international study (35 sites) that included hospitalized patients with symptomatic ICAS (50%–99% luminal stenosis of the intracranial vertebral, basilar, distal internal carotid, or proximal middle cerebral artery) from January 2019 to June 2024. The primary outcome was recurrent ischemic stroke in the territory of the symptomatic artery within 90 days. In the primary analysis, the exposure was an acute anterior circulation borderzone infarct. In secondary analysis of the subset with presentation within 72 hours of last known normal and perfusion imaging completed, the exposure of interest was prespecified as hypoperfusion mismatch volume at T max (time to maximum) threshold of 6 seconds, dichotomized at the Youden index. We performed multivariable Cox regression to test associations between exposure variables and the outcome, adjusting for clinically relevant variables and those associated with the outcome ( P <0.1). RESULTS: Of 2050 patients with symptomatic ICAS, 1737 (84.7%) presented within 72 hours of symptom onset, among whom 509 (29.3%) underwent perfusion imaging. The primary analysis included 1891 patients; 174 (9.2%) patients had recurrent ischemic stroke in the symptomatic arterial territory. In adjusted Cox regression models, there was an association between anterior circulation borderzone infarct and recurrent ischemic stroke at 90 days (adjusted hazard ratio, 1.40 [95% CI, 1.02–1.93]). In the perfusion imaging analysis, hypoperfusion mismatch of ≥10 mL was associated with recurrent ischemic stroke (adjusted hazard ratio, 1.83 [95% CI, 1.03–3.28]). CONCLUSIONS: Biomarkers of impaired distal perfusion, anterior circulation borderzone infarct, and hypoperfusion mismatch were associated with increased risk of recurrent ischemic stroke. These findings support the use of perfusion imaging in ICAS as well as future trials investigating early reperfusion in high-risk patients with ICAS.

Background: Angina with no obstructive coronary arteries (ANOCA) is clinically challenging to diagnose and manage. The agreement between Doppler-derived coronary flow reserve (CFR Doppl ) and PET-derived CFR (CFR PET ) in patients with ANOCA remains unclear. Aims: To evaluate the correlation between Doppler- and PET-derived CFR in patients with ANOCA. Methods: We conducted a single-center, retrospective study of adult patients (age ≥18 years) with ANOCA who were referred for evaluation of possible microvascular ischemia with Doppler- and PET-derived CFR at the Mayo Clinic (Rochester, MN) between January 1, 2018, and May 1, 2024. Pearson correlation was used to quantify the association between Doppler- and PET-derived CFR. Agreement between Doppler- and PET-derived CFR was assessed by Bland-Altman analysis using a 2-way mixed effects model with measures of absolute agreement. Results: A total of 66 patients were initially identified, of which 40 were included in the final analysis (66.7% female, median age 58 years [Q1-Q3: 45-66 years]). Median time between PET- and Doppler-derived CFR was 8 days (Q1-Q3: 1-31 days). Median CFR Doppl was 2.75 (IQR: 2.23-3.28) and median CFR PET was 2.50 (IQR: 2.10-3.10). Doppler-derived CFR displayed a wider range than PET-derived CFR (0.8-5.2 vs 1.2-4.0). A strong correlation was found between Doppler- and PET-derived CFR ( r= 0.81; p<0.001). The corresponding Bland-Altman plot showed an overall bias of 0.27±0.56 (intraclass coefficient=0.85; p<0.001). Conclusions: While invasive coronary angiography with CFR Doppl is the gold-standard for the diagnostic evaluation of ANOCA, PET imaging with CFR PET offers an excellent first line non-invasive modality for diagnosis of coronary microvascular dysfunction.

Introduction: Spontaneous coronary artery dissection (SCAD) is a poorly understood cause of acute coronary syndrome (ACS), predominantly affecting young women and frequently related to acute stressors. It has been suggested that stress induced cardiomyopathy can cause dissection via mechanical distortion of the vessel at wall-motion hinge points. Whether specific coronary anatomic configurations also predispose to distortion and hence SCAD remains unknown. Hypothesis: Patients with left anterior descending (LAD) SCAD have a higher frequency of a “wrap around” (type IV - perfuses >25% of the inferior wall) LAD. Methods: Coronary angiograms of patients in the Mayo Clinic SCAD Registry were reviewed. Patients from functional angiogram registry with similar characteristics were used as controls. Patients with an LAD SCAD were compared to patients who never had an LAD SCAD. For identifying predictors of LAD SCAD, patients who never had an LAD SCAD were compared to patients that had an LAD SCAD as a recurrent event, but not as the initial presentation. Results: A total of 456 patients with SCAD (46±6 years; 96% women) were included. The control group consisted of 178 patients (44±7 years, 97% women). Type IV LAD was more common in the SCAD cohort (Figure 1), and patients in the LAD SCAD group had a higher proportion of type IV LAD when compared to non-LAD SCAD (47.6% vs 23.0% p < 0.001). Bifurcation involvement was also more frequent (48.6 vs 25.8%, p <0.001). Individual predictors of an LAD SCAD during follow-up were diagnosis of hypertension, peripartum SCAD, involvement of a bifurcation and type IV LAD. After multivariate analysis, only bifurcation involvement (OR 2.49, p = 0.01) and type IV LAD (OR 2.26, p = 0.02) remained as predictors of LAD SCAD during follow-up. In patients in whom the PDA perfused the apex (LAD I and II), PDA was more likely to be involved by SCAD (OR 6.17, p<0.001). There were no other differences in coronary distribution after stratifying by LAD types. Conclusions: Type IV LAD variant is more common in patients with LAD SCAD. This finding suggests that coronary anatomic variants predispose to SCAD and lend further support to the mechanical distortion hypothesis.