Prediction of Slow-Flow Phenomenon After Stent Implantation Using Near-Infrared Spectroscopy in Patients With Acute and Chronic Coronary Syndrome.

BACKGROUND: The slow-flow phenomenon is associated with worse clinical outcomes after percutaneous coronary intervention (PCI), so our goal for this study was to see how predictive how near-infrared spectroscopy (NIRS) could be.Methods and Results: We enrolled 179 lesions from 152 patients who had de novo coronary stent implantation guided by NIRS-intravascular ultrasound (IVUS) (male: 69.1%, mean age: 74.3±11.5 years, acute coronary syndrome: 65.1%, diabetes: 42.1%). NIRS automatically determined the maximum 4-mm lipid core burden index (maxLCBI4 mm) value at pre- and post-PCI procedures. The slow-flow phenomenon was defined as the deterioration of TIMI (Thrombolysis in Myocardial Infarction) flows on angiography during the PCI procedure in the absence of mechanical obstruction. The slow-flow phenomenon occurred in 13 (7.3%) lesions, and the slow-flow phenomenon group had a significantly higher maxLCBI4 mm(740±147 vs. 471±223, P<0.001). The best maxLCBI4 mmcutoff point in both acute and chronic coronary syndrome was 578 and 480, with sensitivity of 100%, for predicting the slow-flow phenomenon. In the receiver-operating characteristics analysis, the area under the curve for acute and chronic coronary syndrome was 0.849 and 0.851, respectively. CONCLUSIONS: The results of this study support the utility of NIRS-IVUS-guided PCI for the prediction of the slow-flow phenomenon.

Risk Factors for Vulnerable Plaque Detected Using Near-Infrared Spectroscopy in Patients Receiving Statin Therapy with No History of Coronary Artery Disease.

Residual risk of atherosclerosis remains high despite the use of lipid-lowering therapy with statins. Near-infrared spectroscopy intravascular ultrasound imaging (NIRS-IVUS) can identify vulnerable plaque via the detection of lipid-rich plaque. This study aimed to reveal the clinical characteristics of patients with vulnerable plaque despite statin therapy.NIRS-IVUS was used to determine the maximum 4 mm Lipid Core Burden Index (MaxLCBI4 mm) values of 38 de novo culprit lesions from 32 patients with acute coronary syndrome (53%) (mean age: 73.1 ± 13.1 years) who underwent percutaneous coronary intervention after a minimum 6 months of statin therapy for primary prevention. A patient with vulnerable plaque was defined as an individual presenting at least 1 target lesion with a vulnerable plaque (MaxLCBI4 mm > 400). Overall, the average low-density lipoprotein cholesterol (LDL-C) level was 95.5 ± 27.2 mg/dL. Patients in the vulnerable plaque group were younger and had higher LDL-C, triglycerides, and non-high-density lipoprotein cholesterol (HDL-C) levels than those in the non-vulnerable plaque group. The MaxLCBI4 mm was positively correlated with LDL-C (P = 0.0002), triglycerides (P = 0.0003), and non-HDL-C (P = 0.0001). In multivariate analysis, all 3 treatable lipid components failed to show an independent relationship with the patients with vulnerable plaque. Using receiver-operating characteristics curve analysis, the cutoff points for LDL-C, triglycerides, and non-HDL-C were determined to be 78 mg/dL, 108 mg/dL, and 111 mg/dL, respectively, at MaxLCBI4 mm > 400. In conclusion, this study supports a more comprehensive and aggressive lipid-lowering therapy for the primary prevention of coronary artery disease.

Relationship of quantitative flow ratio after second-generation drug-eluting stent implantation to clinical outcomes.

The correlation of fractional flow reserve, which is presently the gold standard for evaluating myocardial ischemia, with three-dimensional quantitative coronary analysis-based quantitative flow ratio (QFR) is well-known. This study aims to evaluate the relationship of QFR after second-generation drug-eluting stent (2nd gen-DES) implantation to clinical outcomes. A total of 61 consecutive lesions, on which 2nd gen-DES implantation was performed from October 2014 to December 2015, were analyzed. Contrast-flow QFR (c-QFR) was obtained using reliable software (QAngio XA 3D) by modeled hyperemic flow velocity derived from coronary angiography without pharmacologically induced hyperemia. Clinical and angiographic data at the follow-up (18-30 months) were obtained from all cases. c-QFR measurement was possible in 52 (85%) lesions. Of these, clinically-driven target vessel revascularization (TVR) was performed in 8 (15%) lesions. Vessel c-QFR was significantly lower in the TVR group (0.703 ± 0.163 vs. 0.883 ± 0.103, p = 0.016). In the results of the receiver operating characteristics analysis for TVR, area under the curve for vessel c-QFR was 0.857. The cutoff point for the prediction of TVR was defined as vessel c-QFR of ≤ 0.82, the sensitivity of 88%, and specificity of 80%. Conclusion: Vessel c-QFR can predict TVR after 2nd gen-DES implantation. Further investigation is warranted to evaluate whether c-QFR guided coronary intervention ameliorates TVR rate.

Successful Treatment of Refractory Electrical Storm With Landiolol After More Than 100 Electrical Defibrillations.

Electrical storm (ES) was observed in an 82-year-old man with recent myocardial infarction. Conventional therapy, including amiodarone, could not suppress the ES. After more than 100 electrical defibrillations, we were finally able to control the ES with the administration of landiolol. It is known that landiolol can inhibit ES. However, we hesitate to use landiolol in patients with low cardiac output. We would like to emphasize that careful use of landiolol should be considered in patients with refractory ES after myocardial infarction, although cardiac output is severely reduced.