Diagnostic value of angiography-derived index of microcirculatory resistance (AMR) for coronary microcirculatory dysfunction (CMD) and its prognostic significance in patients with chronic coronary syndromes in the smoking population.

This study aims to analyze the prognostic significance of angiographic microvascular resistance (AMR) derived from functional coronary angiography in diagnosing coronary microvascular dysfunction (CMD) among patients with chronic coronary syndrome (CCS), particularly focusing on the prognostic significance of CMD in smokers. Additionally, this study assesses the prognostic significance of the diagnostic accuracy of the AMR index for CMD in CCS patients within the smoking population. Seventy-five CCS patients were studied for IMR measurement between June 2018 and December 2020, classified into CMD and non-CMD groups. Pearson correlation analyzed AMR and IMR relationship, while ROC curves determined AMR's predictive value for CMD with optimal cutoff value. An additional 223 CCS patients were included for AMR measurements. The study's primary endpoint was MACE occurrence, followed up through telephone calls. COX one-way analysis and Kaplan-Meier analysis evaluated the association between AMR and MACE risk. In the study, 52% of patients were diagnosed with CMD, and the AUC under the AMR curve for predicted IMR ≥ 25 was 0.90 (95% CI: 0.79-0.95). The CMD group had a higher proportion of female patients, smokers, and those with hypertension and diabetes mellitus compared to the non-CMD group (all P < .05). The CMD group exhibited higher AMR values than the non-CMD group (3.20 ±â€…0.5 vs 1.95 ±â€…0.45, P < .01), with a significant correlation between AMR and IMR (R2 = 0.81, P < .001). The ROC curve illustrated AMR's effectiveness in diagnosing CMD in CCS patients, using IMR as the gold standard, with the optimal cutoff value of AMR = 2.6mmHgs/cm (sensitivity: 90.5%, specificity: 81.5%). Patients with AMR ≥ 2.6mmHgs/cm had a higher risk of MACE events (HR = 6.00; 95% CI: 1.59-22.67). AMR in patients with CCS was significantly correlated with IMR and demonstrated good diagnostic accuracy. AMR ≥ 2.6 mm Hg*s/cm was associated with an increased risk of MACE occurrence and served as a valuable prognostic factor. In patients with CCS, AMR has a high diagnostic performance, In patients with CCS who smoke, impaired coronary microvascular function as assessed by AMR is significant and is an independent predictor of MACE.

One case of recurrent ST-segment elevation myocardial infarction in a patient with antiphospholipid syndrome complicated with severe thrombocytopenia within a short period of time: A case report.

INTRODUCTION: Acute myocardial infarction is an important arterial thrombotic event in patients with antiphospholipid syndrome (APS). Anticoagulation regimen might greatly affect the prognosis. Due to the lack of sufficient data and large prospective randomized controlled trials, there is no definite consensus among researchers on the optimal antithrombotic therapy for patients with APS after arterial events. PATIENT CONCERNS: A 35-year-old male presented with sustained chest tightness and chest pain for 6 hours, accompanied with palpitation, sweating and headache. DIAGNOSIS: The patients was diagnosed with acute ST-segment elevation myocardial infarctions with severe thrombocytopenia. Emergency coronary angiography showed that the posterior descending artery (PDA) was occluded, and a thrombus shadow was visible. An emergency coronary intervention was performed to open the occluded PDA. About 48 hours after hospitalization, the PDA was occluded again and percutaneous coronary intervention was performed again to open the blocked coronary artery. The lupus anticoagulant screen rate were positive during hospitalization and 12 weeks after discharge, meeting the diagnostic criteria of APS. INTERVENTIONS: The patient received coronary intervention twice during hospitalization. After the second coronary intervention, a sequential therapy of bivalirudin, fondaparinux sodium, and warfarin was adopted as the anticoagulant regimen. OUTCOMES: The patient was discharged in stable condition without chest pain. One year later, during her follow-up, a repeat echocardiogram and electrocardiogram showed normal findings. CONCLUSION: It is the first report of severe thrombocytopenia and recurrent coronary thrombosis within a short period of time in an APS patient, and in this report the importance of anticoagulant therapy in thrombus management in patients with APS was present, also the importance of tracking thrombotic factors. This study proposes an anticoagulation regimen for patients suffering from antiphospholipid syndrome, experiencing recurrent atherothrombotic events, and presenting severe thrombocytopenia.