Faculty Bibliography

BACKGROUND:Coronary functional testing to formally diagnose coronary microvascular dysfunction (CMD) reduces cardiovascular events and alleviates angina. This study aims to investigate the extensive and complex journey that patients with CMD undergo, from the onset of chest pain to eventual diagnosis. METHODS:Data from the Coronary Microvascular Disease Registry (CMDR) were analyzed, including information on the date of first documentation of chest pain, number of non-invasive and invasive tests the patient underwent, emergency department visits, and hospitalizations. In addition, we estimated the total cost per patient. A total of 61 patients with CMD diagnosis were included in this analysis. RESULTS:Most patients in our cohort were older than 50 years of age. The median time from initial chest pain symptoms to diagnosis was 0.62 (interquartile range [IQR]: 0.06-2.96) years. During this period, patients visited the emergency department a median of 1.0 (IQR: 0.0-2.0) times. Diagnostic tests included 3.0 (IQR: 2.0-6.0) electrocardiograms, 3.0 (IQR: 0.0-6.0) high-sensitivity troponin tests, and 1.0 (IQR: 1.0-2.0) echocardiograms. Prior to diagnosis of CMD, 13 (21.3 %) patients had left heart catheterization without coronary functional testing. Non-invasive testing for ischemia was conducted in 43 (70.5 %) patients. Alternative non-cardiac diagnoses were given to 11 (18.0 %) patients during the diagnostic process, with referrals made to gastroenterology for 16 (26.2 %) and pulmonology for 10 (16.4 %) patients. The cost was almost $2000/patient. CONCLUSION/CONCLUSIONS:Timely identification of CMD offers promising opportunities for prompt symptom alleviation, accompanied by reduced visits to the emergency department, cardiovascular testing, invasive medical procedures, and consequently reduced healthcare expenses.

BACKGROUND:Coronary microvascular dysfunction (CMD) is a prevalent condition among patients with cardiovascular risk factors, leading to a reduced quality of life and an increased risk of major adverse cardiovascular events. Novel invasive techniques have emerged to more accurately diagnose CMD. However, CMD's natural history remains poorly understood due to limited data. To address this knowledge gap, the Coronary Microvascular Disease Registry (CMDR) was established with the primary aim of standardizing comprehensive coronary functional testing and understanding of CMD. DESIGN/METHODS:CMDR is a prospective, multicenter registry enrolling an unlimited number of consecutive subjects who undergo comprehensive invasive hemodynamic assessment of the entire coronary arterial vasculature. Patients undergoing acetylcholine provocation test for coronary vasospasm will also be included. Follow-up assessments will be conducted at 30 days and annually for up to 5 years. The primary endpoint is Canadian Cardiovascular Society angina grade over time. Secondary endpoints, including all-cause mortality, cardiovascular death, acute myocardial infarction, stroke, hospitalizations, medication changes, and subsequent coronary interventions, will be analyzed to establish long-term safety and clinical outcomes in patients undergoing invasive CMD assessment. SUMMARY/CONCLUSIONS:CMDR aims to characterize the clinical and physiologic profile of patients undergoing comprehensive invasive coronary functional testing, simultaneously providing crucial longitudinal information on the natural history and outcomes of these patients. This will shed light on CMD's course and clinical implications, which, in turn, holds the potential to significantly improve diagnostic and treatment strategies for CMD patients, ultimately leading to the enhancement of their overall prognosis and quality of life. CLINICAL TRIAL REGISTRATION/BACKGROUND:clinicaltrials.gov, NCT05960474.

BACKGROUND/UNASSIGNED:Patients with complex coronary artery disease, as defined by high SYNTAX scores, undergoing percutaneous coronary intervention (PCI) have poorer outcomes when compared with patients with lower SYNTAX I scores. This study aimed to assess if mechanical circulatory support using Impella mitigates the effect of the SYNTAX I score on outcomes after high-risk percutaneous coronary intervention (HRPCI). METHODS/UNASSIGNED:Using data from the PROTECT III study, patients undergoing Impella-assisted HRPCI between March 2017 and March 2020 were divided into 3 cohorts based on SYNTAX I score-low (≤22), intermediate (23-32), and high (≥33). Procedural and clinical outcomes out to 90 days were compared between groups. Multivariable regression analysis was used to assess the impact of SYNTAX I score on major adverse cardiovascular and cerebrovascular events (MACCE) at 90 days. RESULTS/UNASSIGNED:= .80 vs low). These findings persisted after adjustment for post-PCI SYNTAX I score. CONCLUSIONS/UNASSIGNED:A high SYNTAX I score was associated with higher rates of 90-day MACCE in patients who underwent Impella-assisted HRPCI. Further research is needed to understand the patient and procedural factors driving this finding.

BACKGROUND:Full adoption of coronary microvascular dysfunction (CMD) assessment faces challenges due to its invasive nature and concerns about prolonged procedure time and increased contrast and/or radiation exposure. We compared procedural aspects of CMD invasive assessment to diagnostic left heart catheterization (DLHC) in patients with chest pain who were not found to have obstructive coronary artery disease. METHODS:A total of 227 patients in the Coronary Microvascular Disease Registry were compared to 1592 patients who underwent DLHC from August 2021 to November 2023. The two cohorts were compared using propensity-score matching; primary outcomes were fluoroscopy time and total contrast use. RESULTS:The participants' mean age was 64.1 ± 12.6 years. CMD-assessed patients were more likely to be female (66.5% vs. 45.2%, p < 0.001) and have hypertension (80.2% vs. 44.5%, p < 0.001), history of stroke (11.9% vs. 6.3%, p = 0.002), and history of myocardial infarction (20.3% vs. 7.7%, p < 0.001). CMD assessment was safe, without any reported adverse outcomes. A propensity-matched analysis showed that patients who underwent CMD assessment had slightly higher median contrast exposure (50 vs. 40 mL, p < 0.001), and slightly longer fluoroscopy time (6.9 vs. 4.7 min, p < 0.001). However, there was no difference in radiation dose (209.3 vs. 219 mGy, p = 0.58) and overall procedure time (31 vs. 29 min, p = 0.37). CONCLUSION/CONCLUSIONS:Compared to DLHC, CMD assessment is safe and requires only slightly additional contrast use (10 mL) and slightly longer fluoroscopy time (2 min) without clinical implications. These findings emphasize the favorable safety and feasibility of invasive CMD assessment.

Background: Coronary microvascular dysfunction (CMD) is an etiology for angina with non-obstructive coronary disease. However, the initial adoption of CMD assessment, whether planned or conducted ad hoc, is limited. We characterize planned and ad hoc CMD assessments and highlight evolving trends of a CMD referral center. Methods: We analyzed outpatient data from the Coronary Microvascular Disease Registry from 2021 to 2023. Patients were categorized into planned or ad hoc CMD assessment groups, and baseline characteristics, hospital stay, medications, and physiological measurements were compared. Secondary analysis evaluated a CMD referral center's evolution. Results: Of 101 included outpatients, 67.3 % underwent ad hoc procedures and 32.7 % planned procedures. Average age was 63.1 ± 10.1 years. The planned procedure group was 87.9 % female, and the ad hoc procedure group was 51.5 % female. There were no significant differences in index of microvascular resistance or coronary flow reserve between groups. Hospital stay duration was <1 day for both groups, and neither reported complications. Ad hoc patients were more frequently prescribed aspirin before (64.7 % vs. 36.4 %, p = 0.007) and after the procedure (66.2 % vs. 39.4 %, p = 0.01). CMD rates were higher for planned procedures (30.3 % vs. 10.3 %, p = 0.01). We observed that CMD referral centers have more planned procedures and a higher rate of positive results over time. Conclusion: CMD referral centers' planned procedures, and subsequent positive cases, increased over time. This emphasizes the importance of planned procedures, appropriate patient selection, and increased awareness of CMD among healthcare providers. Clinical trial registration: Coronary Microvascular Disease (CMD) Registry, NCT05960474, https://clinicaltrials.gov/study/NCT05960474

BACKGROUND:Given enough time, transcatheter heart valves (THVs) will degenerate and may require reintervention. Redo transcatheter aortic valve implantation (TAVI) is an attractive strategy but carries a risk of coronary obstruction. AIMS/OBJECTIVE:We sought to predict how many TAVIs patients could undergo in their lifetime using computed tomography (CT) simulation. METHODS:We analysed paired CT scans (baseline and 30 days post-TAVI) from patients in the LRT trial and EPROMPT registry. We implanted virtual THVs on baseline CTs, comparing predicted valve-to-coronary (VTC) distances to 30-day CT VTC distances to evaluate the accuracy of CT simulation. We then simulated implantation of a second virtual THV within the first to estimate the risk of coronary obstruction due to sinus sequestration and the need for leaflet modification. RESULTS:We included 213 patients with evaluable paired CTs. There was good agreement between virtual (baseline) and actual (30 days) CT measurements. CT simulation of TAVI followed by redo TAVI predicted low coronary obstruction risk in 25.4% of patients and high risk, likely necessitating leaflet modification, in 27.7%, regardless of THV type. The remaining 46.9% could undergo redo TAVI so long as the first THV was balloon-expandable but would likely require leaflet modification if the first THV was self-expanding. CONCLUSIONS:Using cardiac CT simulation, it is possible to predict whether a patient can undergo multiple TAVI procedures in their lifetime. Those who cannot may prefer to undergo surgery first. CT simulation could provide a personalised lifetime management strategy for younger patients with symptomatic severe aortic stenosis and inform decision-making. CLINICALTRIALS/RESULTS:gov: NCT02628899; ClinicalTrials.gov: NCT03557242; ClinicalTrials.gov: NCT03423459.

BACKGROUND/PURPOSE/OBJECTIVE:Intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) can identify vulnerable coronary atherosclerotic plaques. We aimed to compare the presence or absence of baseline intravascular imaging of non-culprit lesions and their subsequent adverse events. METHODS/MATERIALS/METHODS:We identified patients from the Lipid Rich Plaque (LRP) study who had a non-culprit-lesion adverse event and divided them into 2 cohorts: those with lesions detected with NIRS-IVUS imaging at baseline and those with lesions not imaged at baseline. RESULTS:Overall, 73 patients had an adverse event (99 coronary segments) during the 24-month follow-up period. Among them, 41 patients (56.2%) had a non-culprit-lesion adverse event related to a coronary segment imaged at baseline, and 32 patients (43.8%) had a non-culprit-lesion adverse event adjudicated to a segment that was not scanned at baseline. Angiographic core laboratory analysis suggested that unscanned lesions were more often in the right coronary artery (~50%); branches of the left coronary artery, i.e., diagonal or left obtuse marginal arteries (~20%); smaller vessels; or more tortuous vessels; and less often in the left anterior descending or distal locations. There was a weak trend for acute severe events (adjudicated myocardial infarction and acute coronary syndrome) in patients with lesions not scanned at baseline (50.0% versus 36.6%, p = 0.250). CONCLUSIONS:In patients with follow-up non-culprit-lesion adverse events, nearly half were not imaged with NIRS-IVUS at baseline. Because events related to non-imaged lesions were at least as severe as events related to imaged lesions, future clinical trials and clinical protocols should be designed to minimize this issue. CLINICAL TRIAL REGISTRATION/BACKGROUND:The Lipid-Rich Plaque Study (LRP), https://clinicaltrials.gov/ct2/show/NCT02033694, NCT02033694.