Distribution of pressure gradients along the left anterior descending artery in patients with angiographically normal arteries.

OBJECTIVES: This study tested the hypothesis that there is no decline of coronary pressure from the proximal to the distal left anterior descending coronary artery (LAD) of humans and swine. BACKGROUND: In the daily clinical practice, the fractional flow reserve (FFR) in the LAD is frequently lower than that in the other arteries in the presence of a similar degree of stenosis. METHODS: Twenty-six patients with angiographically normal LAD were prospectively enrolled. The coronary pressure ratio (mean distal/proximal coronary pressures at hyperemia) was measured at five different positions: 12, 10, 7, and 5 cm distal from the LAD ostium, and at the ostium of the LAD. The coronary pressure measurement was further investigated in a swine model without atherosclerosis. RESULTS: The coronary pressure ratio during maximum hyperemia gradually decreased in proportion to the distance from the ostium (average: 0.85 ± 0.06 at 12 cm distal to the ostium). This finding was confirmed in swine model. The degree of the coronary pressure decrease during maximum hyperemia was similar in patients with and without evidence of minor plaque on intravascular ultrasound, however it was strongly associated with the amount of myocardium mass in the territory of the LAD. CONCLUSIONS: Intracoronary pressure gradually decreases in proportion to the distance from the ostium in the LAD of humans and swine, regardless of the presence of minor atherosclerotic plaques. The degradation degree of the coronary pressure ratio during maximum hyperemia is enlarged in the presence of larger amount of myocardium mass in the territory of the LAD.

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

OBJECTIVES: 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. BACKGROUND: It is unclear whether OCT assessment of stent strut coverage represents endothelial healing after drug-eluting stent implantation. METHODS: Thirty patients with a left anterior descending artery lesion were randomized 1:1:1 to receive an SES, EES, or ZES. The vascular response was evaluated 6 months after stenting by three methods: the functional response by acetylcholine infusion, the morphological response by OCT, and the biological response by measuring vascular endothelial growth factor (VEGF) levels. RESULTS: The proportion of uncovered struts by OCT at 6 months was significantly higher in both SES and EES than in ZES. However, the vasomotor response was impaired and the VEGF level of the coronary sinus was significantly lower in SES than in EES and ZES. There were no relationships between the OCT findings and vasomotor response to acetylcholine and VEGF levels in all cohorts. CONCLUSIONS: The vascular response at 6 months was more preserved in ZES and EES than in SES. Our results suggest that the morphological assessment with OCT may not always be used as a surrogate for functional and biological healing response after stenting. © 2015 Wiley Periodicals, Inc.

Impact of Peak Systolic Velocity Ratio after Drug-Coated Balloon for Femoropopliteal Disease: Three-Month Serial Observation Vessel Echo Study.

AIM: No flow-limiting dissection after drug-coated balloon (DCB) treatment for femoropopliteal (FP) lesions is considered as one of the endpoints, but it has not investigated the difference between each vessel dissection. This study aimed to clarify whether there is a difference between no dissection and type C dissection without flow-limiting dissection for 3 months by peak systolic velocity ratio (PSVR) based on duplex ultrasonography. METHODS: Between February 2020 and April 2021, 44 consecutive de novo FP diseases that underwent endovascular therapy (EVT) with DCB were enrolled in this study. 65.9% of the patients had intermittent claudication, and mean lesion lengths were 194±107 mm. The chronic total occlusion was 38.6%. After DCB treatment, vessel dissection pattern was categorized by angiography. The minimum lumen area (MLA) identified by intravascular ultrasound was serially evaluated with PSVRs at 1 day, 1 month, and 3 months after EVT. RESULT: All lesions were treated with DCB without provisional stents. The vessel dissection pattern after DCB treatment showed that types D, E, and F were not observed, 9% were no dissection, 27% were type A, 32% were type B, and 32% were type C. In all cases, the PSVR values of MLA site were less than 2.6 at 3 months, and there were no significant differences between no dissection and type C dissection. CONCLUSION: Up to dissection pattern "C" is considered acceptable as one of the endpoints to determine the need for provisional stenting after DCB treatment.

The impact of plaque characterization assessed by intravascular ultrasound on myocardial perfusion after primary angioplasty in patients With ST-segment elevation myocardial infarction.

BACKGROUND: Previous studies described that inadequate tissue perfusion after primary angioplasty in ST-elevation myocardial infarction (STEMI) patients is associated with adverse cardiac events. This study evaluated whether plaque morphological intravascular ultrasound (IVUS) characteristics affects tissue perfusion after stent implantation in STEMI patients. METHODS AND RESULTS: A total of consecutive 306 STEMI patients who underwent primary angioplasty with IVUS were analyzed. Maximum ST-segment elevation before angioplasty was compared with ST-segment levels 60min after angioplasty. Percent ST-segment resolution (STR) was calculated and categorized as complete (>70%), partial (30-70%), and absent (<30%). Qualitative and quantitative IVUS analyses were performed using standard methods. Plaque with ultrasound attenuation was defined as IVUS finding with backward signal attenuation behind plaque >180° without dense calcium. One-hundred-fifty patients had complete, 101 had partial, and 55 had absent STR. The incidence of in-hospital death tended to be higher in absent STR than in partial and complete STR groups. Multivariate analysis indicated that remodeling index (P=0.004), the presence of ultrasound attenuation (P=0.02), percentage stent expansion (P=0.03), and the presence of deep calcium (P=0.049) were the independent predictors related to the occurrence of absent STR after angioplasty. CONCLUSIONS: Positive vessel remodeling, plaque with ultrasound attenuation >180°, deep calcium, and stent overexpansion as assessed by IVUS are associated with the absence of STR after primary angioplasty in patients with STEMI.

Assessment of Microvasculature After Intervention as a Predictor of Wound Healing in Patients With Tissue Loss.

OBJECTIVES: This study investigated the correlation between vascular flow reserve (VFR) values and wound healing rate in patients with critical limb ischemia. BACKGROUND: Peripheral VFR may be useful for predicting complete wound healing after endovascular therapy (EVT). However, published reports included small numbers of patients from single centers and long-term outcomes remain unknown. METHODS: This was a prospective multicenter study that consecutively enrolled 104 patients (115 limbs) who received EVT for ischemic ulcerations. All lesions were treated with conventional balloon angioplasty. After EVT, VFR was measured using a pressure/temperature guidewire. The study endpoints were correlation between VFR values and wound healing rate at 3 months and 1 year. RESULTS: The median VFR was 2.9. A total of 110 and 104 limbs completed the 3-month and 1-year follow-up, respectively. The 3-month and 1-year wound healing rates were 49% and 76%, respectively. VFR was significantly associated with the 3-month and 1-year wound healing (p < 0.001 for both). The crude hazard ratios of VFR (per 2-fold increase) for the 3-month and 1-year wound healing were 2.6 (1.7 to 3.9) and 2.9 (2.0 to 4.2), respectively. The estimated median time to wound healing was 5.0 (3.2 to 7.2) months, 3.3 (2.8 to 4.9) months, and 2.5 (2.0 to 3.0) months, when the VFR value was 2.4, 2.9, and 3.9, respectively. CONCLUSIONS: Post-procedure VFR is significantly associated with wound healing. VFR, measured in the catheterization laboratory, is useful in clinical risk stratification for patients with critical limb ischemia after EVT. (Predictor of Wound Healing in Patients with Critical Limb Ischemia-Multicenter Prospective Study; UMIN000012746).

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.

Ex vivo comparison of angioscopy and histopathology for the evaluation of coronary plaque characteristics.

The yellow plaque has been considered to be a vulnerable and high risk for acute coronary syndrome events but not fully evaluated. The aim of this study was to evaluate the relationship between angioscopic color grade and histological features in coronary autopsy specimens. We longitudinally sectioned 110 coronary arteries from 40 autopsy hearts with non-cardiovascular death. Harvested arteries were imaged with intravascular ultrasound to identify the focal plaque (plaque burden >50 %). An angioscopic examination of each focal plaque evaluated its color intensity as follows: 0 (white), 1 (light yellow), 2 (yellow), or 3 (dark yellow). The corresponding histological assessment was classified according to a modified version of the American Heart Association classification of atherosclerosis. Two hundred six plaques were matched to the histological analysis. Of these, 82 (40 %) were categorized as yellow (≥grade 1). Although, yellow plaque often includes thin-cap fibroatheroma (TCFA), the sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy for histological TCFA were 83, 91, 22, 99 and 91 %, respectively. The false-positive coronary angioscopic diagnoses for TCFA that contributed to the low positive predictive value consisted of the following plaques: thick FA (>65 µm), accumulations of large quantities of foam cells on the luminal surface, or dense calcified plates at the surface of the intima. Vulnerable coronary plaques were detected with high sensitivity and low positive predictive value from their yellow color on angioscopy. Not only fibroatheroma but also various types of plaques and their components, such as immature lipidic components and superficial calcium plates, appeared yellow on coronary angioscopy.

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. .

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.

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.

Coronary artery aneurysm formation 7 months after bare-metal stent implantation: Intravascular ultrasound and optical coherence tomography observation.

Late-acquired angiographic coronary aneurysm formation after drug-eluting stent implantation is a rare phenomenon but potentially life-threatening event that has become a major cause of concern. Optical coherence tomography (OCT) is a high-resolution imaging method that allows detailed evaluation of stent strut coverage and characterization of neointimal tissue. This case report describes the possible mechanism of late-acquired angiographic coronary aneurysm formation after bare-metal stent implantation using OCT and intravascular ultrasound.

Intracoronary nicorandil relieves multiple coronary vasospasm with hemodynamic collapse.

A 49-year-old woman was referred to hospital because of chest discomfort. Coronary angiography revealed subtotal occlusion of the left coronary artery and the right coronary artery, but subsequent hemodynamic collapse occurred. Based on the results of intravascular ultrasound the occlusion was suspected to be caused by coronary vasospasm, which was not relieved by intracoronary injection of isosorbide dinitrate (1 mg), but was alleviated by nicorandil (2 mg), a potassium-channel opener. After discharge from hospital, the patient stopped taking her medication and returned complaining of chest discomfort again. Intravenous verapamil (5 mg) did not improve it, but direct intracoronary administration of nicorandil (2 mg) did bring relief. This case suggests that nicorandil is effective for coronary vasospasm.

Elevation of the ratio of transmitral E velocity to early diastolic mitral annular velocity continues even after recovery from acute stage in patients with diastolic heart failure.

BACKGROUND: Clinical features of diastolic heart failure (DHF) have not been well characterized, leading to an inaccuracy in the diagnosis of DHF. Recently, the ratio of transmitral E velocity to early diastolic mitral annular velocity (E/E') has been shown to be useful to assess LV filling pressure. PURPOSE: We tested the hypothesis that persistent elevation of E/E' ratio is one of the characteristics of patients with DHF. METHODS: Candidates of this study were 89 patients who presented to the emergency department because of acute pulmonary congestion. Those with an ejection fraction of >45% on admission comprised the DHF group (n=18). A control group consisted of consecutive 30 hypertensive patients with an ejection fraction of >45%. Doppler echocardiographic data were obtained with plasma BNP measure in the chronic stage >6 months after the emergent admission. RESULTS: The E/E' ratio was higher in the DHF group than in the control group (16.7±2.8 vs. 9.4±3.3, p<0.01). BNP level was also elevated in the DHF group. CONCLUSION: A persistent elevation of E/E' ratio may be an indicator of patients with or at risk of DHF among subjects with preserved systolic function independent of LV hypertrophy.

Fourteen month follow-up angioscopic findings of a sirolimus-eluting stent implanted in a 15-year-old saphenous vein graft.

Saphenous vein grafts (SVGs) are common, as is their degeneration and early failure after coronary artery bypass graft surgery (CABG). Percutaneous SVG intervention with drug-eluting stents (DES) was associated with superior short-term clinical outcomes. However, SVG intervention compared with coronary intervention often results in distal embolisation and periprocedural myocardial infarction. In this case, we discuss 9 and 14 month follow-up neointimal coverage of a DES implanted in a 15 year-old SVG and other morphological changes using angioscopy.

Angioscopic findings of delayed healing at sites of sirolimus-eluting stent overlap after 21-month implantation.

Treatment of de novo coronary stenosis with sirolimus-eluting stents is associated with very low rates of target lesion revascularization and other major adverse cardiac events in the short-term after implantation, but a definite frequency of late-stent thrombosis (LST) over a long-term follow-up has become evident. One of the predictors of LST is stent overlap. We reported the angioscopic findings of very delayed healing at sites of sirolimus-eluting stent overlap 21 months post-implantation.