These findings suggested that neither abnormalities in the coronary circulation nor acute myocarditis was related to the etiology. Although neurogenic stunned myocardium induced by emotional or physical stress was suggested as the etiology, further investigations are necessary.

Objective To evaluate the relation of symptom onset to balloon time and door to balloon time with long term clinical outcome in patients with ST segment elevation myocardial infarction (STEMI) having primary percutaneous coronary intervention.Design Observation of large cohort of patients with acute myocardial infarction.Setting 26 tertiary hospitals in Japan.Participants 3391 patients with STEMI who had primary percutaneous coronary intervention within 24 hours of symptom onset. Main outcome measuresComposite of death and congestive heart failure, compared by onset to balloon time and door to balloon time. ResultsCompared with an onset to balloon time greater than 3 hours, a time of less than 3 hours was associated with a lower incidence of a composite of death and congestive heart failure (13.5% (123/964) v 19.2% (429/2427), P<0.001; relative risk reduction 29.7%). After adjustment for confounders, a short onset to balloon time was independently associated with a lower risk of the composite endpoint (adjusted hazard ratio 0.70, 95% confidence interval 0.56 to 0.88; P=0.002). However, no significant difference was found in the incidence of a composite of death and congestive heart failure between the two groups of patients with short (≤90 minutes) and long (>90 minutes) door to balloon time (16.7% (270/1671) v 18.4% (282/1720), P=0.54; relative risk reduction 9.2%). After adjustment for confounders, no significant difference was seen in the risk of the composite endpoint between the two groups of patients with short and long door to balloon time (adjusted hazard ratio: 0.98, 0.78 to 1.24: P=0.87). A door to balloon time of less Correspondence to: Y Nakagawa nakagawa@tenriyorozu.jp Extra material supplied by the author (see

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Aims To investigate local haemodynamics in the setting of acute coronary plaque rupture and erosion. Methods and Results Intracoronary optical coherence tomography performed in 37 patients with acute coronary syndromes caused by plaque rupture (n = 19) or plaque erosion (n = 18) was used for 3D reconstruction and computational fluid dynamic simulation. Endothelial shear stress (ESS), spatial ESS gradient (ESSG), and oscillatory shear index (OSI) were compared between plaque rupture and erosion through mixed-effects logistic regression. Lipid, calcium, macrophages, layered plaque, and cholesterol crystals were also analysed. By multivariable analysis, only high ESSG (odds ratio [OR] 5.29, 95% confidence interval [CI] 2.57-10.89, p &lt; 0.001), lipid (OR 12.98, 95% CI 6.57-25.67 p &lt; 0.001), and layered plaque (OR 3.17, 95% CI 1.82-5.50, p &lt; 0.001) were independently associated with plaque rupture. High ESSG (OR 13.28, 95% CI 6.88-25.64, p &lt; 0.001), ESS (OR 2.70, 95% CI 1.34-5.42, p = 0.005) and OSI (OR 2.18, 95% CI 1.33-3.54, p = 0.002) independently associated with plaque erosion. ESSG was higher at rupture sites than erosion sites (median (interquartile range): 5.78 (2.47, 21.15) versus 2.62 (1.44, 6.18) Pa/mm, p = 0.009), OSI was higher at erosion sites than rupture sites (1.04x10−2 (2.3x10−3, 4.74x10−2) versus 1.29x10−3 (9.39x10−5, 3.0x10−2), p &lt; 0.001), but ESS was similar (p = 0.29). Conclusions High ESSG is independently associated with plaque rupture while high ESSG, ESS, and OSI associate with plaque erosion. While ESSG is higher at rupture sites than erosion sites, OSI is higher at erosion sites and ESS was similar. These results suggest that ESSG and OSI may play critical roles in acute plaque rupture and erosion, respectively. Translational Perspective Plaque rupture and erosion are distinct pathological and clinical entities with possibly different optimal treatments. This study demonstrates that high endothelial shear stress gradient is independently associated with site of both rupture and erosion, and is significantly higher in rupture. High oscillatory shear index is independently associated with the site of erosion only, and is higher in erosion than rupture. Larger studies are necessary to determine whether these indices may detect and distinguish plaque rupture and erosion in a clinical setting or to assess overall risk for acute coronary syndromes.

on behalf of the CREDO-Kyoto PCI/ CABG Registry Cohort-2 Investigators Background-Optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation has not been yet fully elucidated. Methods and Results-We assessed the influence of prolonged thienopyridine therapy on clinical outcomes with landmark analysis at 4 and 13 months after DES implantation. Among 6802 patients with at least 1 DES implantation in the CREDO-Kyoto Registry Cohort-2, 6309 patients (on thienopyridine, 5438 patients; off thienopyridine, 871 patients) and 5901 patients (on thienopyridine, 4098 patients; off thienopyridine, 1803 patients) were eligible for the 4-and 13-month landmark analyses, respectively. The majority of patients had stable coronary artery disease (73%) and received sirolimus-eluting stents (93%), and approximately 90% of thienopyridine was ticlopidine. Patients taking thienopyridine had more complex comorbidities and more complex lesion and procedural characteristics as compared with patients not taking thienopyridine. After adjusting for confounders, thienopyridine use was not associated with decreased risk for death/myocardial infarction/stroke (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.89 -1.43, Pϭ0.32 in the 4-month landmark analysis; HR, 1.14; 95% CI, 0.90 -1.45, Pϭ0.29 in the 13-month landmark analysis, respectively), whereas the risk for GUSTO moderate/severe bleeding tended to be higher in patients taking thienopyridine (HR, 1.51; 95% CI, 1.00 -2.23, Pϭ0.049 in the 4-month landmark analysis; HR, 1.44; 95% CI, 0.99 -2.09, Pϭ0.057 in the 13-month landmark analysis, respectively). Conclusions-Prolonged thienopyridine therapy beyond 4 and 13 months appeared not to be associated with reduction in ischemic events but to be associated with a trend toward increased bleeding. Optimal duration of DAPT after DES implantation might be shorter than the currently recommended 1-year interval. (Circ Cardiovasc Interv. 2012;5:381-391.)

BackgroundDespite a moderate correlation between angiographical stenosis and physiological significance, the mechanism of discordance has not been fully elucidated, particularly regarding the significance of microvascular function. This study sought to clarify whether microvascular function affects visual‐functional mismatch between quantitative coronary angiography (QCA) and fractional flow reserve (FFR).Methods and ResultsWe assessed QCA, FFR, coronary flow reserve, and the index of microcirculatory resistance in 849 non‐left‐main coronary lesions with visually estimated intermediate stenoses from 532 patients. Clinical and lesion‐specific characteristics and physiological parameters associated with mismatch and reverse mismatch were studied. Coronary flow reserve and index of microcirculatory resistance showed a weak, but significant, correlation with FFR (R=0.306, P<0.001 and R=0.158, P<0.001, respectively). Four hundred twenty‐two lesions were visually nonsignificant (diameter stenosis assessed by QCA [QCA‐DS] ≤50%) and 427 lesions were visually significant (QCA‐DS >50%). Among visually nonsignificant lesions, FFR ≤0.80 (reverse mismatch) was observed in 129 lesions (30.6%). Among visually significant lesions, FFR >0.80 (mismatch) were observed in 179 lesions (41.9%). The significant predictors of reverse mismatch were male sex, nonculprit lesions of acute coronary syndrome, left anterior descending artery location, smaller QCA reference diameter, greater QCA‐DS, lower coronary flow reserve, and lower index of microcirculatory resistance. Mismatch was associated with right coronary artery location, greater QCA reference diameter, smaller QCA‐DS, lesion length, higher coronary flow reserve, and higher index of microcirculatory resistance.ConclusionsThere was a high prevalence of visual‐functional mismatches between QCA and FFR. The discrepancy was related to clinical characteristics, lesion‐specific factors, and microvascular resistance that was undistinguishable by coronary angiography, thus suggesting the importance of physiological lesion assessment.

This study investigates whether hyperemic microvascular resistance (MR) is influenced by elective percutaneous coronary intervention (PCI) by using the index of microcirculatory resistance (IMR). Seventy-one consecutive patients with stable angina pectoris undergoing elective PCI were prospectively studied. The IMR was measured before and after PCI and at the 10-mo follow-up. The IMR significantly decreased until follow-up; the pre-PCI, post-PCI, and follow-up IMRs had a median of 19.8 (interquartile range, 14.6-28.9), 16.2 (11.8-22.1), and 14.8 (11.8-18.7), respectively (P < 0.001). The pre-PCI IMR was significantly correlated with the change in IMR between pre- and post-PCI (r = 0.84, P < 0.001) and between pre-PCI and follow-up (r = 0.93, P < 0.001). Pre-PCI IMR values were significantly higher in territories with decreases in IMR than in those with increases in IMR [pre-PCI IMR: 25.4 (18.4-35.5) vs. 12.5 (9.4-16.8), P < 0.001]. At follow-up, IMR values in territories showing decreases in IMR were significantly lower than those with increases in IMR [IMR at follow-up: 13.9 (10.9-17.6) vs. 16.6 (14.0-21.4), P = 0.013]. The IMR decrease was significantly associated with a greater shortening of mean transit time, indicating increases in coronary flow (P < 0.001). The optimal cut-off values of pre-PCI IMR to predict a decrease in IMR after PCI and at follow-up were 16.8 and 17.0, respectively. In conclusion, elective PCI affected hyperemic MR and its change was associated with pre-PCI MR, resulting in showing a wide distribution. Overall hyperemic MR significantly decreased until follow-up. The modified hyperemic MR introduced by PCI may affect post-PCI coronary flow.

Stable right diaphragmatic CMAPs could be obtained, and monitoring CMAPs might be useful for anticipating right PNI during SVC isolation.