Tsuyoshi Nakata

Thermodilution-Derived Coronary Blood Flow Pattern Immediately After Coronary Intervention as a Predictor of Microcirculatory Damage and Midterm Clinical Outcomes in Patients With ST-Segment–Elevation Myocardial Infarction

Background—Despite a sufficient coronary blood flow after primary percutaneous coronary intervention for patients with ST-segment–elevation myocardial infarction; some patients have a poor outcome because of microcirculatory damage. This study evaluates whether the thermodilution-derived coronary blood flow parameters immediately after primary percutaneous coronary intervention predict early microvascular damage and midterm outcomes in patients with ST-segment–elevation myocardial infarction. Methods and Results—Using a pressure sensor/thermistor-tipped guidewire, we measured the index of microcirculatory resistance at maximum hyperemia, and coronary blood flow pattern was assessed from the thermodilution curves after successful primary percutaneous coronary intervention in 88 patients with ST-segment–elevation myocardial infarction. Coronary blood flow pattern was classified into 3 groups according to the shape of thermodilution curve: a narrow unimodal (n=41), a wide unimodal (n=32), or bimodal (n=15). All patients had contrast-enhanced cardiac magnetic resonance scans within 2 weeks. The index of microcirculatory resistance values were significantly higher both in a wide unimodal and in a bimodal groups than in a narrow unimodal group (65±41 and 76±38 versus 20±9U; P<0.001). Bimodal group had higher prevalence of microvascular obstruction on contrast-enhanced cardiac magnetic resonance when compared with the other groups (100%, 78%, and 30%; P<0.001). Patients in bimodal group had a higher risk of death and heart failure rehospitalization at 6 months (73%, 6.3%, 7.3%; P<0.001). Multivariate analysis revealed that bimodal shape of the thermodilution curve was the only independent predictor of cardiac death at 6 months after ST-segment–elevation myocardial infarction (P<0.01). Conclusions—A bimodal shape of the thermodilution curve, which may indicate myocardial edema and consequent extrinsic compression of the capillary network, is associated with microcirculatory damage and poor midterm clinical outcomes rather than index of microcirculatory resistance value itself.

Multiple complex coronary atherosclerosis in diabetic patients with acute myocardial infarction: a three-vessel optical coherence tomography study

AIMS The main cause of acute myocardial infarction (AMI) is the disruption of a thin-cap fibroatheroma (TCFA) and subsequent thrombosis. Mortality increases in diabetic patients due to cardiovascular events; there may be differences in the vulnerable plaques between diabetic and non-diabetic patients. We used optical coherence tomography (OCT) to assess the incidence of vulnerable plaques in diabetic patients with AMI. METHODS AND RESULTS OCT was performed in all three major coronary arteries of 70 AMI patients: 48 non-diabetic and 22 diabetic patients. The OCT criterion for TCFA was the presence of both a lipid-rich plaque composition and a fibrotic cap thickness of <65 µm. A ruptured plaque contains a cavity in contact with a lumen and a residual fibrous cap. OCT identified 68 plaque ruptures (1.0 per patient; range, 0-3) and 162 TCFAs (2.3 per patient; range, 0-5). The incidences of plaque rupture and TCFA at culprit lesions were similar. However, non-culprit-lesion TCFAs were observed more frequently in diabetic patients than in non-diabetic patients. CONCLUSIONS Although the prevalence of vulnerable plaque in culprit lesions was similar between diabetic and non-diabetic patients, vulnerable plaques were observed in non-culprit lesions more in diabetic patients than in non-diabetic patients.

Morphological, Functional, and Biological Vascular Healing Response 6 Months After Drug-Eluting Stent Implantation: A Randomized Comparison of Three Drug-Eluting Stents.

This study evaluated coronary endothelial function after the implantation of sirolimus‐eluting stents (SESs), everolimus‐eluting stents (EESs), and zotarolimus‐eluting stents (ZES) by a different methodology, and also analyzed whether optical coherence tomography (OCT) findings represent endothelial healing after stenting.

Primary cardiac malignant fibrous histiocytoma with abdominal wall metastasis

We present a rare case of cardiac malignant fibrous histiocytoma (MFH; undifferentiated pleomorphic sarcoma); to date, fewer than 100 cases of cardiac MFH have been reported. In this case, transthoracic echocardiography revealed cardiac tumors in the left atrium (LA) of a 53-year-old woman with a 3-month history of worsening dyspnea; the largest tumor was found to protrude through the mitral valve in diastole, causing stenosis. Three of the four tumors were resected during emergency surgery; however, the residual tumor extension into the left pulmonary vein could not be removed. Histological findings of the resected tumors, such as organized thrombus and myxomatous tissue changes, indicated that the tumors were benign. After 3 months, the patient underwent total resection for a small mass that developed on her right abdominal wall, which was revealed histologically to be MFH; additionally, the residual mass in the LA had enlarged progressively. After undergoing radiation therapy without further surgery, she died of cerebral bleeding 6 months after cardiac surgery. Postmortem examination revealed that the tumor in the LA was an MFH. Thus, cardiac MFH should be considered as a differential diagnosis for tumors on the posterior wall of the LA. <Learning objective: Primary cardiac malignant fibrous histiocytoma (MFH), which is easily mistaken for atrial myxoma, is a rare type of cardiac sarcoma. MFH occurs most commonly on the posterior wall of the left atrium (LA), and total resection is currently the only effective therapy; however, the prognosis is poor. Therefore, a high level of suspicion is required to facilitate early diagnosis. Cardiac MFH should be considered as a differential diagnosis for tumors on the posterior wall of the LA.>.

The utility of intravascular ultrasound for the diagnosis and management of spontaneous coronary artery dissection in a middle-aged woman with acute inferior myocardial infarction

Spontaneous coronary artery dissection (SCAD) is an infrequent cause of acute myocardial ischemia and is associated with various pathophysiologies, such as pregnancy, postpartum, and collagen diseases. It is frequently fatal and most cases are diagnosed at autopsy. Therefore, the early diagnosis of SCAD and initiation of treatment may be life saving. In this report, we describe a case of SCAD of right coronary artery, possibly triggered by transient high blood pressure, with no apparent atherosclerotic involvement detected by intravascular ultrasound (IVUS) and successfully treated with stent implantation. The IVUS helped us to confirm the diagnosis, navigate the guidewire into the true lumen, and understand the mechanism for the appearance of a lotus root formation.

Clinical Effects of Planned Endovascular Therapy for Critical Limb Ischemia Patients with Tissue Loss

Aim: The aim of this study was to investigate the clinical effect of planned endovascular therapy (EVT) for critical limb ischemia (CLI) patients with tissue loss. Although several rounds of EVT for CLI patients are required for complete wound healing, time required for complete wound healing depends on the wound severity. We hypothesized that planned EVT might reduce the time to wound healing. Methods: A total of 89 limbs of 76 CLI patients with tissue loss, who had undergone more than at least two EVTs were included in this study. From January 2013 through December 2015 (Conventional-EVT-group, 52 limbs), indication of target lesion revascularization (TLR) was decided based on decreased skin perfusion pressure (SPP) values or delayed wound healing. From January 2016 through October 2016 (Planned-EVT-group, 37 limbs), TLR were done every two months regardless of the SPP values until complete wound healing was obtained. Time to wound healing and complete wound healing rates were compared between the two groups. Results: No significant differences existed in baseline patients and lesion characteristics between the two groups. There was no significant difference in total EVT numbers between the two groups (2.0; interquartile range, 2.0–3.0 versus 2.0; interquartile range, 2.0–3.0; P = 0.9). Although complete wound healing rate was similar in both groups (71.2% versus 73.0%, p = 1.0), time to wound healing was significantly shorter (95 days versus 143 days, p = 0.025) in the Planned-EVT-group than in the Conventional-EVT-group. Conclusions: Planned-EVT is a useful strategy to shorten the time to wound healing for CLI patients with tissue loss.

Impact of low tissue backscattering by optical coherence tomography on endothelial function after drug-eluting stent implantation

This study evaluated the impact of optical coherence tomography (OCT)-derived low-backscattered tissue on mid-term coronary endothelial function after drug-eluting stent (DES) implantation. Although OCT enables detailed in vivo evaluation of neointimal tissue characterization after DES implantation, its association with physiological vascular healing response is unclear. Thirty-three stable angina pectoris patients underwent OCT examination and endothelial function testing with intracoronary infusion of incremental doses of acetylcholine 8-month after DES implantation in a single lesion of the left anterior descending artery. Neointimal tissue was classified into two patterns based on the predominant OCT light backscatter: high backscatter and low backscatter. Although the presence of uncovered or malapposed stent strut was not associated with the degree of vasoconstriction, the degree of vasoconstriction was significantly greater in the DES with low-backscattered neointima than in the DES without low-backscattered neointima (− 32.1 ± 25.7 vs. − 4.1 ± 20.1%, p = 0.003). Moreover, there was an inverse linear relationship between low backscatter tissue index and degree of vasoconstriction after acetylcholine infusion (r = 0.50 and p = 0.003). The endothelium-dependent vasomotor response after 8-month of DES was impaired in patients with low neointimal tissue backscatter on OCT imaging. OCT assessment of low-backscattered tissue may be used as surrogate markers for impairment of endothelial function after DES.

Comparison of the OUTBACK® Elite Reentry Catheter and the Bi-directional Approach after Failed Antegrade Approach for Femoro-popliteal Occlusive Disease

Aim: A successful antegrade wire crossing for femoro-popliteal chronic total occlusion (FP-CTO) is still a technical challenge. We attempted to demonstrate the safety and feasibility of the OUTBACK® Elite reentry catheter and the bi-directional approach for failed FP-CTO cases with the antegrade approach. Methods: Endovascular therapy for FP-CTO was performed in 219 lesions from May 2013 to December 2016 at Morinomiya Hospital. We retrospectively analyzed the data of 43 consecutive lesions which underwent endovascular therapy using the bi-directional approach with distal access and the mono-directional approach with the OUTBACK® Elite reentry catheter for FP-CTO lesions. The antegrade success using a combination of traditional and Intravascular Ultrasound (IVUS) -guided techniques was achieved in 170 lesions out of a total of 219 lesions. From May 2013 to June 2016 (phase 1), the bi-directional approach with distal access was applied to 22 lesions after failed antegrade approaches. From July 2016 to December 2016 (phase 2), the mono-directional approach with the OUTBACK® Elite reentry catheter was applied to 21 lesions. Results: Clinical and lesion characteristics in phase 1 were not significantly different from those in phase 2. The overall initial technical success rate was 100% in both phases. The total wire number and amount of contrast media were significantly less, and the total procedure time and the total fluoroscopic time were significantly shorter in phase 2 than in phase 1 (p < 0.01). Conclusions: Endovascular therapy for FP-CTO using the OUTBACK® Elite reentry catheter is feasible and safe after a failed antegrade approach.

Response to letter regarding article, "Thermodilution-derived coronary blood flow pattern immediately after coronary intervention as a predictor of microcirculatory damage and midterm clinical outcomes in patients with ST-segment-elevation myocardial infarction".

We thank Drs Echavarria-Pinto and Escaned1 for their interest in our article.2 To analyze coronary blood flow pattern, thermodilution curves need to be obtained by brisk injection of 3 mL of room temperature saline by hand into the coronary artery through the guiding catheter at steady-state hyperemia.3 As pointed by Drs Echavarria-Pinto and Escaned,1 however, the shape of thermodilution …

ELEVATED CONCENTRATIONS OF PENTRAXIN-3 ARE ASSOCIATED WITH NEOINTIMAL TISSUE CHARACTERIZATION OF RESTENOSIS LESIONS AFTER BARE-METAL AND DRUG-ELUTING STENT IMPLANTATION

Although optical coherence tomography (OCT) studies reported various patterns of restenotic tissue after bare–metal (BMS) and drug–eluting stents (DES) implantation, the clinical significance of these tissue is unknown. OCT was performed to assess intimal tissue morphology in