Index of Microcirculatory Resistance to predict microvascular obstruction in STEMI: A systematic review and meta-analysis.

BACKGROUND: Microvascular obstruction (MVO) is an independent predictor of adverse cardiac events after ST-elevation myocardial infarction (STEMI). The Index of Microcirculatory Resistance (IMR) may be a useful marker of MVO, which could simplify the care pathway without the need for Cardiac Magnetic Resonance (CMR). We assessed whether the IMR can predict MVO in STEMI patients. METHODS AND RESULTS: We conducted a systematic review and meta-analysis, including articles where invasive IMR was performed post primary percutaneous coronary intervention (PCI) in addition to MVO assessment with cardiac MRI. We searched PubMed, Scopus, Embase, and Cochrane databases from inception until January 2023. Baseline characteristics, coronary physiology and cardiac MRI data were extracted by two independent reviewers. The random-effects model was used to pool the data. Among 15 articles identified, nine articles (n = 728, mean age 61, 81% male) contained IMR data stratified by MVO. Patients with MVO had a mean IMR of 41.2 [95% CI 32.4-50.4], compared to 25.3 [18.3-32.2] for those without. The difference in IMR between those with and without MVO was 15.1 [9.7-20.6]. Meta-regression analyses demonstrated a linear relationship between IMR and TIMI grade (ß = 0.69 [0.13-1.26]), as well as infarct size (ß = 1.18 [0.24-2.11]) or ejection fraction at 6 months (ß = -0.18 [-0.35 to -0.01]). CONCLUSION: In STEMI, patients with MVO had 15-unit higher IMR than those without. IMR also predicts key prognostic endpoints such as infarct size, MVO, and long-term systolic function.

Coronary perforation incidence, outcomes and temporal trends (COPIT): a systematic review and meta-analysis.

Coronary perforation is a potentially life-threatening complication of percutaneous coronary intervention (PCI). We studied incidence, outcomes and temporal trends following PCI-related coronary artery perforation (CAP). METHODS: Prospective systematic review and meta-analysis including meta-regression using MEDLINE and EMBASE to November 2020. We included 'all-comer' PCI cohorts including large PCI registries and randomised controlled trials and excluding registries or trials limited to PCI in high-risk populations such as chronic total occlusion PCI or cohorts treated only with atheroablative devices. Regression analysis and corresponding correlation coefficients were performed comparing perforation incidence, mortality rate, tamponade rate and the rate of Ellis III perforations against the midpoint (year) of data collection to determine if a significant temporal relationship was present. RESULTS: 3997 studies were screened for inclusion. 67 studies met eligibility criteria with a total of 5 568 191 PCIs included over a 38-year period (1982-2020). The overall pooled incidence of perforation was 0.39% (95% CI 0.34% to 0.45%) and remained similar throughout the study period. Around 1 in 5 coronary perforations led to tamponade (21.1%). Ellis III perforations are increasing in frequency and account for 43% of all perforations. Perforation mortality has trended lower over the years (7.5%; 95% CI 6.7% to 8.4%). Perforation risk factors derived using meta-regression were female sex, hypertension, chronic kidney disease and previous coronary bypass grafting. Coronary perforation was most frequently caused by distal wire exit (37%) followed by balloon dilation catheters (28%). Covered stents were used to treat 25% of perforations, with emergency cardiac surgery needed in 17%. CONCLUSION: Coronary perforation complicates approximately 1 in 250 PCIs. Ellis III perforations are increasing in incidence although it is unclear whether this is due to reporting bias. Despite this, the overall perforation mortality rate (7.5%) has trended lower in recent years. Limitations of our findings include bias that may be introduced through analysis of multidesign studies and registries without pre-specified standardised perforation reporting CMore research into coronary perforation management including the optimal use of covered stents seems warranted. PROSPERO REGISTRATION NUMBER: CRD42020207881.

Early-onset post-cardiotomy severe constrictive pericarditis: a case report.

Background: Constrictive pericarditis (CP) can be one of the most challenging conditions to diagnose within cardiovascular medicine. Iatrogenic causes of CP are increasingly recognized in higher income countries. This case provides insight into the need for clinical suspicion when diagnosing this relatively under recognized clinical entity as well as the need for multimodality imaging combined with invasive haemodynamic assessment. Case summary: A 68-year-old man presented with decompensated heart failure 4 weeks after open-heart surgery. A diagnosis of early-onset post-cardiotomy CP was made using multimodality imaging and invasive haemodynamic assessment, which demonstrated the cardinal features of constrictive physiology. Surgical intervention with two pericardiectomy procedures was pursued given the aggressive and recalcitrant nature of his presentation. Our patient died shortly after his second surgery due to progressive multi-organ dysfunction. Conclusion: Constrictive pericarditis is a challenging but important clinical entity to diagnose. Differentiating CP from restrictive cardiomyopathy is important as there are key differences in management and prognosis. Our case supports the clinical utility of multimodality imaging combined with invasive haemodynamic assessment in patients with suspected CP.

Proteasome inhibitor-induced coronary vasospasm in multiple myeloma: a case report.

BACKGROUND: Coronary vasospasm is an increasingly recognized cause of myocardial infarction or myocardial ischaemia in patients without obstructive coronary artery disease. A thorough medication review may identify drugs or toxins that could trigger coronary vasospasm. This case provides mechanistic insight into the off-target effect of proteasome inhibition leading to coronary vasospasm in a patient referred with chest pain consistent with typical angina. CASE SUMMARY: A 72-year-old lady presented with anginal chest pain at rest with electrocardiogram evidence of myocardial ischaemia who was referred for invasive coronary angiography. This demonstrated minor coronary disease without an obstructive lesion. Vasoreactivity testing revealed diffuse coronary vasospasm of the left anterior descending artery. Carfilzomib was identified as the trigger for coronary vasospasm. Symptoms resolved without recurrence after appropriate treatment including cessation of the triggering agent. CONCLUSION: Coronary spasm is a rare but important adverse reaction to proteasome inhibitors. This case supports the clinical utility of invasive coronary vasoreactivity testing in patients with ischaemia with no obstructive coronary artery disease.