Seong-Ill Woo

Randomised trial to compare a protective effect of Clopidogrel Versus TIcagrelor on coronary Microvascular injury in ST-segment Elevation myocardial infarction (CV-TIME trial).

AIMS Ticagrelor has shown greater, more rapid and more consistent platelet inhibition than clopidogrel. However, the superiority of ticagrelor for preventing ischaemic damage in STEMI patients has not been proven. The aim of this trial was to assess whether ticagrelor is superior to clopidogrel in preventing microvascular injury in ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS Patients with STEMI underwent prospective random assignment to receive a loading dose (LD) of clopidogrel 600 mg or ticagrelor 180 mg (1:1 ratio) before primary percutaneous coronary intervention (PCI). As the primary endpoint, the index of microcirculatory resistance (IMR) was measured immediately after primary PCI. The secondary endpoint was the infarct size estimated from the wall motion score index (WMSI). A total of 76 patients were enrolled (clopidogrel group=38, ticagrelor group=38). The IMR in the ticagrelor group was significantly lower than that in the clopidogrel group (22.2±18.0 vs. 34.4±18.8 U, p=0.005). Cardiac enzymes were less elevated in the ticagrelor group than in the clopidogrel group (CK peak; 2,651±1,710 vs. 3,139±2,698 ng/ml, p=0.06). Infarct size, estimated by WMSI, was not different between the ticagrelor and clopidogrel groups at baseline (1.55±0.30 vs. 1.61±0.29, p=0.41) or after three months (1.42±0.33 vs. 1.47±0.33, p=0.57). CONCLUSIONS In patients with STEMI treated by primary PCI, a 180 mg LD of ticagrelor might be more effective in reducing microvascular injury than a 600 mg LD of clopidogrel, as demonstrated by IMR immediately after primary PCI.

Comprehensive assessment of microcirculation after primary percutaneous intervention in ST-segment elevation myocardial infarction: insight from thermodilution-derived index of microcirculatory resistance and coronary flow reserve

ObjectivesA pathophysiological mechanism of microvascular dysfunction in ST-segment elevation myocardial infarction (STEMI) is multifactorial; thus, multiple modalities were needed to precisely evaluate a microcirculation. MethodsWe complementarily assessed microcirculation in STEMI by the index of microcirculatory resistance (IMR) and coronary flow reserve (CFR) immediately after a primary percutaneous intervention in 89 STEMI patients. Cardiovascular and cerebrovascular events (MACCE) including cardiovascular death, target vessel failure, heart failure, and stroke were assessed during a mean follow-up period of 3.0 years. ResultsThe microcirculation of enrolled patients was classified into four groups using cutoff CFR and IMR values (CFR>2 and mean IMR): group-1 (n=23, CFR>2 and IMR⩽27); group-2 (n=31, CFR⩽2 and IMR⩽27); group-3 (n=9, CFR>2 and IMR>27); and group-4 (n=26, CFR<2 and IMR>27). On echocardiography 3 months later, improvement in the wall motion score index was shown in group-1 (P<0.01), group-2 (P<0.01), and group-3 (P=0.04), whereas group-4 did not show improvement in wall motion score index (P=0.06). During clinical follow-up, there were no MACCE in group-1 and the patients in group-2 and group-3 showed significantly lower MACCE compared with group-4 (group-1=0%, group-2, and group-3=10%, group-4=23.1%, P=0.04). ConclusionComplimentary assessment of microcirculation by the IMR and CFR may be useful to evaluate myocardial viability and the long-term prognosis of STEMI patients.

Clinical and Echocardiographic Factors Affecting Tricuspid Regurgitation Severity in the Patients with Lone Atrial Fibrillation.

Background Atrial fibrillation (AF) can be a risk factor for development of significant tricuspid regurgitation (TR). We investigated which clinical and echocardiographic parameters were related to severity of functional TR in patients with lone AF. Methods A total of 89 patients with lone AF were enrolled (75 ± 11 years; 48% male): 13 patients with severe TR, 36 patients with moderate TR, and 40 consecutive patients with less than mild TR. Clinical parameters and echocardiographic measurements including right ventricular (RV) remodeling and function were evaluated. Results Patients with more severe TR were older and had more frequently persistent AF (each p < 0.001). TR severity was related to right atrial area and tricuspid annular systolic diameter (all p < 0.001). The patients with moderate or severe TR had larger left atrial (LA) volume and increased systolic pulmonary artery pressure (SPAP) than the patients with mild TR (p = 0.04 for LA volume; p < 0.001 for SPAP). RV remodeling represented by enlarged RV area and increased tenting height was more prominent in severe TR than mild or moderate TR (all p < 0.001). Multivariate analysis showed type of AF, LA volume, tricuspid annular diameter and tenting height remained as a significant determinants of severe TR. In addition, tenting height was independently associated with the presence of severe TR (p = 0.04). Conclusion In patients with lone AF, TR was related to type of AF, LA volume, tricuspid annular diameter and RV remodeling. Especially, tricuspid valvular tethering seemed to be independently associated with development of severe functional TR.

Long-term clinical and angiographic outcomes after implantation of sirolimus-eluting stents with a "modified mini-crush" technique in coronary bifurcation lesions.

We aimed to evaluate long‐term outcomes of a modified mini‐crush technique for treating bifurcation lesions.

Comparing the effect of clopidogrel versus ticagrelor on coronary microvascular dysfunction in acute coronary syndrome patients (TIME trial): study protocol for a randomized controlled trial.

BackgroundAlthough prompt reperfusion treatment restores normal epicardial flow, microvascular dysfunction may persist in some patients with acute coronary syndrome (ACS). Impaired myocardial perfusion is caused by intraluminal platelets, fibrin thrombi and neutrophil plugging; antiplatelet agents play a significant role in terms of protecting against thrombus microembolization. A novel antiplatelet agent, ticagrelor, is a non-thienopyridine, direct P2Y12 blocker that has shown greater, more rapid and more consistent platelet inhibition than clopidogrel. However, the effects of ticagrelor on the prevention of microvascular dysfunction are uncertain. The present study is a comparison between clopidogrel and ticagrelor use for preventing microvascular dysfunction in patients with ST elevation or non-ST elevation myocardial infarction (STEMI or NSTEMI, respectively).Methods/designThe TIME trial is a single-center, randomized, open-label, parallel-arm study designed to demonstrate the superiority of ticagrelor over clopidogrel. A total of 152 patients with a spectrum of STEMI or NSTEMI will undergo prospective random assignment to clopidogrel or ticagrelor (1:1 ratio). The primary endpoint is an index of microcirculatory resistance (IMR) measured after percutaneous coronary intervention (PCI); the secondary endpoint is wall motion score index assessed at 3 months by using echocardiography.DiscussionThe TIME trial is the first study designed to compare the protective effect of clopidogrel and ticagrelor on coronary microvascular dysfunction in patients with STEMI and NSTEMI.Trial registrationClinicalTrials.gov: NCT02026219. Registration date: 24 December 2013.

Successful coronary stent retrieval from the ascending aorta using a gooseneck snare kit

Coronary stent dislodgement is a rare complication of percutaneous coronary intervention. We report a case of stent dislodgement in the ascending thoracic aorta. The stent was mechanically distorted in the left circumflex artery (LCX) while being delivered to the proximal LCX lesion. The balloon catheter was withdrawn, but the stent with the guide wire was remained in the ascending thoracic aorta. The stent was unable to be retrieved into the guide catheter, as it was distorted. A goose neck snare was used successfully to catch the stent in the ascending thoracic aorta and retrieved the stent externally via the arterial sheath.

Clinical and Angiographic Predictors of Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction.

Purpose We aimed to discover clinical and angiographic predictors of microvascular dysfunction using the index of microcirculatory resistance (IMR) in patients with ST-segment elevation myocardial infarction (STEMI). Materials and Methods We enrolled 113 patients with STEMI (age, 56±11 years; 95 men) who underwent primary percutaneous coronary intervention (PCI). The IMR was measured with a pressure sensor/thermistor-tipped guidewire after primary PCI. The patients were divided into three groups based on IMR values: Low IMR [<18 U (12.9±2.6 U), n=38], Mid IMR [18-31 U (23.9±4.0 U), n=38], and High IMR [>31 U (48.1±17.1 U), n=37]. Results The age of the Low IMR group was significantly lower than that of the Mid and High IMR groups. The door-to-balloon time was <90 minutes in all patients, and it was not significantly different between groups. Meanwhile, the symptom-onset-to-balloon time was significantly longer in the High IMR group, compared to the Mid and Low IMR groups (p<0.001). In the high IMR group, the culprit lesion was found in a proximal location significantly more often than in a non-proximal location (p=0.008). In multivariate regression analysis, age and symptom-onset-to-balloon time were independent determinants of a high IMR (p=0.013 and p=0.003, respectively). Conclusion Our data suggest that age and symptom-onset-to-balloon time might be the major predictors of microvascular dysfunction in STEMI patients with a door-to-balloon time of <90 minutes.

Epicardial Artery Stenosis with a High Index of Microcirculatory Resistance Is Frequently Functionally Insignificant as Estimated by Fractional Flow Reserve (FFR).

Objective Differences in microvascular integrity can diversely influence the functional assessment of epicardial coronary artery disease in each patient. We investigated the relevance of the index of microcirculatory resistance (IMR) and fractional flow reserve (FFR) of intermediate coronary lesions. Methods The IMR and FFR were measured in 67 intermediate coronary lesions of the left anterior descending artery of 67 patients, by using a pressure sensor/thermistor-tipped guidewire. Results To assess the differences in FFR in relationship to the IMR value, patients were divided into tertile IMR groups as follows: Low-IMR (n=22, IMR 14±3), Mid-IMR (n=23, IMR 21±2), and High-IMR (n=22, IMR 36±10). An analysis of variance showed that the High-IMR group had significantly higher FFR values (0.87±0.07) than the Low-IMR group (0.81±0.08) (p=0.03). Functionally significant lesions with FFR ≤0.8 accounted for 9% of lesions in the High-IMR group, 36% in the Low-IMR group and 22% in the Mid-IMR group (p=0.02). In the multivariate logistic analysis, the IMR value was an independent determinant of FFR ≤0.8 (p=0.03). Conclusion In patients with a high IMR, intermediate lesions as identified with visual estimation were more frequently functionally insignificant. The IMR can provide additional information in understanding the mismatch between the anatomical and functional severity of intermediate coronary stenosis.

Anomalous origin of the left circumflex artery from the right sinus of valsalva: non-ST-segment elevation myocardial infarction.

An anomalous origin of the left coronary artery from the right sinus of Valsalva (RSV) is rare. We herein report the case of an 80-year-old woman who presented to the emergency department with chest pain. Emergent coronary angiography was performed following a diagnosis of non-ST segment elevation myocardial infarction. A right coronary angiogram showed that the common trunk originating from the RSV branched into the left anterior descending and right coronary arteries. Although the initial angiogram failed to show the left circumflex artery (LCx), considered to be the culprit vessel, computed tomographic angiography demonstrated that the LCx was located immediately below the common trunk and exhibited a retroaortic course. We successfully treated the patient and obtained optimal angiography results.

A Case of Endovascular Treatment of Severe Graft Limb Kinking after Endovascular Abdominal Aortic Aneurysm Repair

Endovascular aneurysm repair (EVAR) has been recommended as an alternative to open aneurysm repair. The risk of severe perioperative complications is lower than that in open surgical repair; however, late complications are more likely. After EVAR, regular yearly surveillance by duplex ultrasonography or computed tomography is recommended. We report the case of a 67-year-old man with a severely kinked left iliac branch of the stent graft 10 years after EVAR. He had not undergone regular follow-up during the last 4 years. We realigned the endograft kink by percutaneous transluminal angioplasty.