The no-reflow phenomenon associated with percutaneous coronary intervention: its mechanisms and treatment

The ATRIA and Modified-ATRIA Scores in Evaluating the Risk of No-Reflow in Patients With STEMI Undergoing Primary Percutaneous Coronary Intervention

The no-reflow (NR) phenomenon is frequently encountered in acute coronary syndrome. We evaluated the association between anticoagulation and risk factors in atrial fibrillation (ATRIA) and modified ATRIA risk scores and NR in ST-elevation myocardial infarction (STEMI). Consecutive patients (n = 551) who underwent primary percutaneous coronary intervention between December 2019 and June 2020 due to STEMI were included. The mean age of the patients was 60.5 ± 10.8 years (n = 369, 67% male). The ATRIA and modified anticoagulation and risk factors in atrial fibrillation-hyperlipidemia, smoking, male (m-ATRIA-HS) scores were calculated. The NR group had higher frequency of diabetes mellitus (DM), serum creatine kinase-MB (CK-MB) levels, and corrected thrombolysis in myocardial infarction frame count (cTFC) (P = .002, P = .006, and P < .001, respectively). In regression analysis, ATRIA, m-ATRIA-HS, thrombus grade, and cTFC were independent predictors of NR. Age, higher CK-MB, and neutrophil-to-lymphocyte ratio and DM were the other predictors for NR. Pairwise comparison of receiver operating characteristics curve analysis showed that the m-ATRIA-HS (>2, area under curve [AUC]: 0.715) has better performance than ATRIA score (>1, AUC: 0.656), with a P < .022 and z statistics 2.279. In conclusion, ATRIA, especially the m-ATRIA-HS, can be used to evaluate NR risk in STEMI.

The impact of the excimer laser on myocardial salvage in ST-elevation acute myocardial infarction via nuclear scintigraphy

Data on the efficacy of excimer laser coronary atherectomy (ELCA) for patients with ST-elevation myocardial infarction (STEMI) are limited. Therefore, we sought to evaluate the impact of ELCA on myocardial salvage using nuclear scintigraphy in patients with STEMI. Between September 2014 and April 2017, we retrospectively enrolled 316 consecutive patients undergoing primary PCI (p-PCI) after their first STEMI in our institute. Of those, 72 patients with STEMI, an initial thrombolysis in myocardial infarction (TIMI) flow-0/1, and an onset to balloon time (OBT) < 6 h were included (ELCA, n = 32; non-ELCA, n = 40). The endpoint was the myocardial salvage index (MSI) based on a 17-segment model with a 5-point scoring system. MSI was calculated as: MSI = (∑¹²³I-BMIPP defect score at 3-7 days after p-PCI - ∑^99mTc-tetrofosmin defect score at 3-6 months after p-PCI)/∑¹²³I-BMIPP defect score × 100 (%) at 3-7 days after p-PCI. The groups were compatible except in age (ELCA: 62.9 ± 12.4 years vs. non-ELCA: 69.8 ± 11.0 years) and loading antiplatelet drug (prasugrel: 100% vs. 40.0%). Direct implantation of shorter stents more frequently occurred in the ELCA group than in the non-ELCA group. MSI seemed to be better in the ELCA group compared with the non-ELCA group (57.6% vs. 45.6%, p = 0.09). This trend was emphasized when the final TIMI-3 flow was achieved (67.1% vs. 45.7%, p = 0.01). The nuclear scintigraphy results showed that ELCA can potentially improve myocardial salvage in patients with STEMI with OBT < 6 h and initial TIMI flow-0/1.

Increased serum adiponectin predicts improved coronary flow and clinical outcomes in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention

Background

Previous studies suggested that adiponectin (APN) could ameliorate ischemia/reperfusion injury and endothelial dysfunction in patients with acute myocardial infarction. However, the relationship between serum APN level and coronary flow after primary percutaneous coronary intervention (PPCI) in patients with ST‐segment elevation myocardial infarction (STEMI) is unclear.

Methods

A total of 144 patients with STEMI treated by PPCI were enrolled and divided into two groups based on the mean serum APN level on admission. The data on coronary angiograms and laboratory examinations were collected and compared between groups. The incidence of major adverse cardiac events (MACE) was evaluated in all enrolled patients.

Results

The prevalence of Thrombolysis In Myocardial Infarction (TIMI) flow grade <3 after PPCI and corrected TIMI frame count were lower in the high‐APN group (P = 0.032 and P = 0.029, respectively). Logistic regression analysis demonstrated that APN was an independent negative predictor of poor coronary flow after PPCI (odds ratio = 0.72, 95% CI: 0.56‐0.93, P = 0.011). Kaplan‐Meier curves showed that a higher APN level correlated with a better MACE‐free survival rate, and multivariate Cox hazard regression analysis indicated that high APN was a significant negative predictor of MACE (hazard ratio = 0.54, 95% CI: 0.29‐1.00, P = 0.048).

Conclusion

Elevated serum levels of APN on admission are associated with improved myocardial blood flow and clinical outcomes in STEMI patients treated with PPCI.

A case of coronary microvascular spasm with slow flow induced by the intracoronary acetylcholine provocation test

Microvascular angina is a rare condition in which myocardial ischemia is caused by microvascular dysfunction without any abnormalities of the epicardial coronary arteries. In clinical practice, it is difficult to diagnose because the microvascular alterations cannot be detected by conventional angiography. Herein we present a rare case of a 67-year-old woman with unstable angina pectoris in whom considerably slow coronary flow was induced by the acetylcholine provocation test with mild epicardial arterial spasm, suggesting the presence of microvascular spasm. Moreover, we show that β-methyl-p-[(123)I]-iodophenyl-pentadecanoic ((123)I-BMIPP) single-photon emission computed tomography imaging is useful for proving myocardial ischemia.

Sinus dysfunction after stent implantation in the right coronary artery immediately recovered after reflow in the sinus node artery

A 67-year-old man who had a history of syncope was admitted because of effort angina. The sinus node (SN) was the single blood supply from the right coronary artery (RCA). After we implanted 2 everolimus-eluting stents for RCA, slow-flow occurred and the SN artery was occluded, and junctional escape rhythm was sustained. After the wiring to the occluded SN artery, junctional escape rhythm immediately recovered to sinus rhythm, and the patient achieved continuous sinus rhythm and stable hemodynamics. Given that acute SN ischemia is a possible cause of sinus dysfunction, careful choice of a percutaneous coronary intervention strategy should be taken into consideration if the SN artery is the single blood supply from the RCA and if syncopal history is present.

Successful prevention of no-reflow phenomenon in a high-risk patient using excimer laser coronary atherectomy

During the treatment of coronary artery disease, the no-reflow phenomenon can lead to severe impairment of viable cardiac muscle and all necessary measures should be taken to prevent it. Excimer laser coronary atherectomy (ELCA) may be indicated for lesions with a large thrombus burden due to potential to ablate thrombi and necrotic plaques. However, there are few reports on the use of ELCA for the prevention of distal embolism. Here, we report a case involving severe left ventricular dysfunction with a previous extensive anterior infarction, where ELCA was used in the right coronary artery to prevent the no-reflow phenomenon.

Safety and feasibility of high-dose administration of nicorandil before reperfusion therapy in acute myocardial infarction

The efficacy and safety of high-dose nicorandil therapy in acute myocardial infarction (AMI) have not yet been clarified. This is a prospective study including 30 patients who received nicorandil at 0.06 mg/kg/h [standard dose nicorandil (SDN) group] and 32 patients who received a bolus injection of nicorandil 0.2 mg/kg followed by a continuous infusion at 0.2 mg/kg/h [high-dose nicorandil (HDN) group]. The benefits and adverse events were assessed during acute phase and 12-month follow-up period. There were no significant differences between the groups in blood pressure, heart rate or urine volume 2, 6 and 24 h after drug administration, although blood pressure decreased during acute phase. The percentages of patients who required dose reduction or discontinuation of nicorandil were 34.4 and 16.7 % in HDN and SDN groups, respectively (p = 0.11). In HDN group, subgroup analysis revealed that the TIMI frame count (TFC) was significantly lower in patients in whom the treatment was started within 12 h compared to those more than 12 h (17.0 vs. 21.0, p = 0.017) and in patients with baseline WBC elevation compared to those without it (16.5 vs. 22.0, p = 0.029). A TFC of >20 was significantly associated with being in HDN group [odds ratio (OR) 0.27; 95 % confidence interval, CI 0.07-0.89], onset-to-balloon time (OR 1.06; 95 % CI 1.01-1.16), and ∑creatine kinase (OR 7.27; 95 % CI 1.40-57.83). There were no significant differences in incidences of cardiovascular death, rehospitalization, and target lesion revascularization between the groups. HDN therapy may improve coronary microcirculation in patients with AMI.