Association of moderate chronic kidney disease with insufficient improvement of fractional flow reserve after stent implantation.

OBJECTIVES: This study aims to investigate the association of moderate chronic kidney disease (CKD) with fractional flow reserve (FFR) after stent implantation. BACKGROUND: Patients with moderate CKD have a higher prevalence of severe and diffuse coronary artery disease, and have increased risk of cardiovascular events even after stent implantation. On the other hand, in some patients, FFR could not be sufficiently improved even after stent implantation. However, the association between these pathophysiological processes is unclear. METHODS AND RESULTS: A total of 102 patients with stable angina, in whom a stent was implanted for the left anterior descending coronary artery (LAD) lesion, were included. Patients with a severely decreased glomerular filtration rate (GFR; > CKD stage 4) were excluded. Patients were stratified into 3 groups: those with an estimated GFR (eGFR) ≥ 60 mL per min per 1.73 m(2) (stage 0-2), 45 to 59 mL per min per 1.73 m(2) (stage 3a), and 30 to 44 mL per min per 1.73 m(2) (stage 3b). FFR after stent implantation (post-stent FFR) was significantly lower in the stage 3b group than in both the stage 0-2 group and the stage 3a group (P < 0.01). Post-stent FFR had a significant positive correlation with eGFR (r = 0.223, P = 0.024). Multivariate analysis demonstrated that eGFR was an independent predictor of post-stent FFR. CONCLUSIONS: Moderate CKD was independently associated with insufficient improvement of FFR after stent implantation. This can partly explain the poor prognosis of patients with CKD. © 2015 Wiley Periodicals, Inc.

Papaverine-induced polymorphic ventricular tachycardia during coronary flow reserve study of patients with moderate coronary artery disease.

BACKGROUND: Papaverine is useful for evaluating the functional status of a coronary artery, but it may provoke malignant ventricular arrhythmia (VA). The aim of this study was to investigate the incidence, and clinical and ECG characteristics of patients with papaverine-induced VAs. METHODS AND RESULTS: The 182 consecutive patients underwent fractional flow reserve (FFR) measurement of 277 lesions. FFR was determined after intracoronary papaverine administration by standard procedures. The clinical and ECG characteristics were compared between patients with and without ventricular tachycardia (VT: ≥3 successive premature ventricular beats (PVBs), or ventricular fibrillation (VF)). After papaverine administration, the QTc interval, QTUc interval, and T-peak to U-end interval were prolonged significantly. Single PVBs on the T-wave or U-wave type developed in 29 patients (15.9%). Polymorphic VT (torsade de pointes) occurred in 5 patients (2.8%), and of those, VF developed in 3 patients (1.7%). No clinical and baseline ECG parameters were predictors for VT or VF except for sex and administration of papaverine into the left coronary artery. Excessive prolongation of QT (or QTU), T-peak to U-end intervals and giant T-U waves were found immediately prior to the ventricular tachyarrhythmias (VTAs), which were unpredictable from the baseline data. CONCLUSIONS: Intracoronary administration of papaverine induced fatal VTAs, although the incidence is rare. Excessive prolongation of the QT (and QTU) interval appeared prior to VTAs; however, they were unpredictable.

Real-time use of instantaneous wave-free ratio: results of the ADVISE in-practice: an international, multicenter evaluation of instantaneous wave-free ratio in clinical practice.

OBJECTIVES: To evaluate the first experience of real-time instantaneous wave-free ratio (iFR) measurement by clinicians. BACKGROUND: The iFR is a new vasodilator-free index of coronary stenosis severity, calculated as a trans-lesion pressure ratio during a specific period of baseline diastole, when distal resistance is lowest and stable. Because all previous studies have calculated iFR offline, the feasibility of real-time iFR measurement has never been assessed. METHODS: Three hundred ninety-two stenoses with angiographically intermediate stenoses were included in this multicenter international analysis. Instantaneous wave-free ratio and fractional flow reserve (FFR) were performed in real time on commercially available consoles. The classification agreement of coronary stenoses between iFR and FFR was calculated. RESULTS: Instantaneous wave-free ratio and FFR maintain a close level of diagnostic agreement when both are measured by clinicians in real time (for a clinical 0.80 FFR cutoff: area under the receiver operating characteristic curve [ROC(AUC)] 0.87, classification match 80%, and optimal iFR cutoff 0.90; for a ischemic 0.75 FFR cutoff: iFR ROC(AUC) 0.90, classification match 88%, and optimal iFR cutoff 0.85; if the FFR 0.75-0.80 gray zone is accounted for: ROC(AUC) 0.93, classification match 92%). When iFR and FFR are evaluated together in a hybrid decision-making strategy, 61% of the population is spared from vasodilator while maintaining a 94% overall agreement with FFR lesion classification. CONCLUSION: When measured in real time, iFR maintains the close relationship to FFR reported in offline studies. These findings confirm the feasibility and reliability of real-time iFR calculation by clinicians.

[Nephrotic syndrome in patients after successful myeloablative allogeneic hematopoietic stem cell transplantation: clinical findings obtained from four transplanted patients].

We experienced four patients who suffered from nephrotic syndrome after a successful allogeneic hematopoietic stem cell transplantation (HSCT). These cases were seen in the nineteen-year period from September, 1986 to June, 2005. Our data showed that the incidence of nephrotic syndrome was 0.51% (3 out of 585 HSCT patients) in our hospital. Pathological findings of their renal biopsy specimens revealed that 3 patients had membranous nephropathy and that one patient had minimal change disease. Three patients were positive for anti nuclear antibody. Administration of prednisolone or cyclosporine improved the nephrotic syndrome, leading all patients to a complete or almost complete remission. The nephrotic syndrome occurred at 17 to 25 months after HSCT and accompanied the relapse of chronic graft-versus-host disease (GVHD), possibly due to the termination or a decrease of immunosuppressant administration in all patients. This suggests that immunological abnormality associated with chronic GVHD may be partly involved.

Analysis of suboptimal stent deployment using intravascular ultrasound and coronary pressure pullback measurement.

BACKGROUND: There are some cases in whom a sufficient improvement in fractional flow reserve (FFR) could not be achieved even if anatomical results indicated satisfactory stent deployment. We investigated the relation of abnormal findings between intravascular ultrasound (IVUS) and coronary pressure pullback measurement (CP-PB). METHODS: IVUS and CP-PB were investigated after stent deployment in 60 vessels in 53 patients. CP-PB criterion for adequate stent deployment was defined as a ratio of coronary pressure at the stent distal edge to the proximal edge (Psd/Psp) that is greater than 0.95. RESULTS: Residual pressure gradient across the stent which was indicated by Psd/Psp≤0.95 was present in 11 (18%), and four of them were caused by insufficient stent expansion (incomplete apposition and asymmetric dilation), and five of them were caused by issues with stent edge (edge dissection and incomplete coverage of the plaques). Insufficient FFR recovery which was recorded at distal part of target vessel was present in 10 (17%), and the main causes corresponded to inadequate stent deployment in half of the lesions, and presence of residual lesion at a non-stent segment in the other half. There were six lesions in whom Psd/Psp was ≤0.95 but FFR was ≥0.80. Disagreement between IVUS and CP-PB findings was seen in 12 (20%). CONCLUSIONS: Residual pressure gradient across the stent can reflect not only an insufficient stent expansion but also issues with stent edges. The decision of optimum stent deployment as assessed by IVUS and CP-PB was mismatched in 20% of cases, therefore careful attention should be paid to decoding the CP-PB findings.

Seven-year clinical outcomes of patients with moderate coronary artery stenosis after deferral of revascularization based on gray-zone fractional flow reserve.

The range (0.75-0.80) of fractional flow reserve (FFR) is known as the gray zone. Although the FFR of 0.80 was recently adopted as the cutoff value for coronary revascularization, the long-term clinical outcomes of patients with angiographically moderate coronary artery stenosis (FFR: 0.75-0.80) remain unknown. The objective of the present study was to investigate the clinical outcomes of patients with angiographically moderate coronary artery stenosis, whose FFR was 0.75-0.80. One hundred and twenty consecutive patients, for whom coronary revascularization was deferred based on FFR, were categorized to groups I and II, in which 55 and 65 patients had FFRs of 0.75-0.80 and 0.81-0.85, respectively. Adverse cardiac events included all-cause death, cardiac death, myocardial infarction, coronary revascularization for the FFR-measured and -unmeasured arteries, congestive heart failure, and admission for chest symptoms. Patients were followed up for 7 years after coronary angiography. Event-free survival rates of all adverse cardiac events were 73 % in group I and 63 % in group II (P = 0.35) and those of adverse cardiac events related to the FFR-measured artery were 94 and 85 % (P = 0.08). Throughout the follow-up period, the medication rate of statins was significantly lower in group II than in group I (P = 0.008). Seven-year clinical outcomes of patients with the gray-zone FFR were good. Furthermore, FFR-measured artery-related events in patients with the gray-zone FFR tended to occur less frequently than in patients with better FFR of 0.81-0.85. Optimal medical therapy is required for them, regardless of coronary stenosis severity and FFR.

The total urine protein-to-creatinine ratio can predict the presence of microalbuminuria.

BACKGROUND: The Kidney Disease: Improving Global Outcomes chronic kidney disease (CKD) guidelines recommend that CKD be classified based on the etiology, glomerular filtration rate (GFR) and degree of albuminuria. The present study aimed to establish a method that predicts the presence of microalbuminuria by measuring the total urine protein-to-creatinine ratio (TPCR) in patients with cardiovascular disease (CVD) risk factors. METHODS AND RESULTS: We obtained urine samples from 1,033 patients who visited the cardiovascular clinic at St. Luke's International Hospital from February 2012 to August 2012. We measured the TPCR and the urine albumin-to-creatinine ratio (ACR) from random spot urine samples. We performed correlation, receiver operating characteristic (ROC) curve, sensitivity, and subgroup analyses. There was a strong positive correlation between the TPCR and ACR (R2 = 0.861, p<0.001). A ROC curve analysis for the TPCR revealed a sensitivity of 94.4%, a specificity of 86.1%, and an area under the curve of 0.903 for detecting microalbuminuria for a TPCR cut-off value of 84 mg/g of creatinine. The subgroup analysis indicated that the cut-off value could be used for patients with CVD risk factors. CONCLUSIONS: These results suggest that the TPCR with an appropriate cut-off value could be used to screen for the presence of microalbuminuria in patients with CVD risk factors. This simple, inexpensive measurement has broader applications, leading to earlier intervention and public benefit.