Effects of stent postdilatation during primary PCI for STEMI: Insights from coronary physiology and optical coherence tomography.

OBJECTIVES: This study aimed to assess the impact of stent optimization by NC-balloon postdilatation (PD) during primary-PCI for STEMI with the use of coronary physiology and intracoronary imaging. METHODS: This was a prospective observational study (ClinicalTrials.gov:NCT02788396). Optical coherence tomography (OCT) and physiological measurements were performed immediately before and after PD with the operators blinded to all measurements. The index of microcirculatory resistance (IMR), coronary flow reserve (CFR) and fractional flow reserve (FFR) were measured. OCT analysis was performed for assessment of stent expansion, malapposition, in-stent plaque-thrombus prolapse (PTP) and stent-edge dissections (SED). The change in IMR before and after PD as a measure of microvascular injury was the primary objective of the study. RESULTS: Thirty-two STEMI patients undergoing primary-PCI had physiological measurements before and after PD. All patients received second-generation DES (diameter 3.1 ± 0.5 mm, length 29.9 ± 10.7 mm) and postdilatation with NC-balloons (diameter 3.6 ± 0.6 mm, inflation pressure 19.3 ± 2.0 atm). IMR (44.9 ± 25.6 vs. 48.8 ± 34.2, p = 0.26) and CFR (1.60 ± 0.89 vs. 1.58 ± 0.71, p = 0.87) did not change, while FFR increased after PD (0.91 ± 0.08 vs. 0.93 ± 0.06, p = 0.037). At an individual patient level, IMR increased in half of the cases. PD improved significantly absolute and relative stent expansion, reduced malapposition, and increased PTP. There was no difference in clinically relevant SED. CONCLUSION: In this exploratory, hypothesis-generating study, postdilatation during primary-PCI for STEMI improved stent expansion, apposition and post-PCI FFR, without a significant effect on coronary microcirculation overall. Nevertheless, IMR increased in a group of patients and larger studies are warranted to explore predictors of microcirculatory response to postdilatation.

Contemporary management of stent thrombosis: Predictors of mortality and the role of new-generation drug-eluting stents.

OBJECTIVES: We sought to evaluate mortality predictors and the role of new-generation drug-eluting stents (NG-DES) in stent thrombosis (ST) management. BACKGROUND: No data are available regarding the outcome of patients with ST after interventional management that includes exclusively NG-DES. METHODS: Patients with definite ST of DES or BMS who underwent urgent/emergent angiography between 2015 and 2018 at our institution were considered for the study. After excluding patients who achieved TIMI-flow<2 after intervention or received an old-generation stent, 131 patients were included. Management classification was stent or non-stent treatment (medical management, thromboaspiration, balloon-angioplasty). Follow-up was performed to document all-cause death (ACD) and target-lesion-revascularization (TLR) that was used for censorship. RESULTS: Mode of presentation was STEMI in 88% and UA/NSTEMI in 12%. Type of ST was early, late, and very late in 11, 4, and 85%, respectively. Eighty four patients received stent and 47 non-stent treatment. After 926 ± 34 days, 21 ACDs, 7 TLRs and no cases of definite, recurrent ST were observed. Univariate predictors of in-hospital mortality were LVEF and presentation with shock or cardiac arrest. For patients discharged alive, non-stent treatment (HR 4.2, p = .01), TIMI-2 flow (HR 7.4, p = .002) and GFR < 60 mL/min (HR 3.8, p = .01) were independent predictors of ACD. The stent-treatment group had significantly better ACD-free survival after discharge, both unadjusted (p = .022) and adjusted (p = .018). CONCLUSIONS: After ST management, different predictors were observed for in-hospital mortality and mortality in patients discharged alive. The better outcome with NG-DES treatment is a novel observation, warranting further studies to elucidate if it is associated with stent-related or patient-related factors.

Coronary artery height differences and their effect on fractional flow reserve.

BACKGROUND: Fractional flow reserve (FFR) uses pressure-based measurements to assess the severity of a coronary stenosis. Distal pressure (Pd) is often at a different vertical height to that of the proximal aortic pressure (Pa). The difference in pressure between Pd and Pa due to hydrostatic pressure, may impact FFR calculation. METHODS: One hundred computed tomography coronary angiographies were used to measure height differences between the coronary ostia and points in the coronary tree. Mean heights were used to calculate the hydrostatic pressure effect in each artery, using a correction factor of 0.8 mmHg/cm. This was tested in a simulation of intermediate coronary stenosis to give the "corrected FFR" (cFFR) and percentage of values, which crossed a threshold of 0.8. RESULTS: The mean height from coronary ostium to distal left anterior descending (LAD) was +5.26 cm, distal circumflex (Cx) -3.35 cm, distal right coronary artery-posterior left ventricular artery (RCA-PLV) -5.74 cm and distal RCA-posterior descending artery (PDA) +1.83 cm. For LAD, correction resulted in a mean change in FFR of +0.042, -0.027 in the Cx, -0.046 in the PLV and +0.015 in the PDA. Using 200 random FFR values between 0.75 and 0.85, the resulting cFFR crossed the clinical treatment threshold of 0.8 in 43% of LAD, 27% of Cx, 47% of PLV and 15% of PDA cases. CONCLUSIONS: There are significant vertical height differences between the distal artery (Pd) and its point of normalization (Pa). This is likely to have a modest effect on FFR, and correcting for this results in a proportion of values crossing treatment thresholds. Operators should be mindful of this phenomenon when interpreting FFR values.

Impact of point-of-care pre-procedure creatinine and eGFR testing in patients with ST segment elevation myocardial infarction undergoing primary PCI: The pilot STATCREAT study.

BACKGROUND: Contrast-induced acute kidney injury (CI-AKI) is a recognised complication during primary PCI that affects short and long term prognosis. The aim of this study was to assess the impact of point-of-care (POC) pre-PPCI creatinine and eGFR testing in STEMI patients. METHODS: 160 STEMI patients (STATCREAT group) with pre-procedure POC testing of Cr and eGFR were compared with 294 consecutive retrospective STEMI patients (control group). Patients were further divided into subjects with or without pre-existing CKD. RESULTS: The incidence of CI-AKI in the whole population was 14.5% and not different between the two overall groups. For patients with pre-procedure CKD, contrast dose was significantly reduced in the STATCREAT group (124.6ml vs. 152.3ml, p=0.015). The incidence of CI-AKI was 5.9% (n=2) in the STATCREAT group compared with 17.9% (n=10) in the control group (p=0.12). There was no difference in the number of lesions treated (1.118 vs. 1.196, p=0.643) or stents used (1.176 vs. 1.250, p=0.78). For non-CKD patients, there was no significant difference in contrast dose (172.4ml vs. 158.4ml, p=0.067), CI-AKI incidence (16.7% vs. 13.4%, p=0.4), treated lesions (1.167 vs. 1.164, p=1.0) or stents used (1.214 vs. 1.168, p=0.611) between the two groups. CONCLUSIONS: Pre-PPCI point-of-care renal function testing did not reduce the incidence of CI-AKI in the overall group of STEMI patients. In patients with CKD, contrast dose was significantly reduced, but a numerical reduction in CI-AKI was not found to be statistically significant. No significant differences were found in the non-CKD group.

Comparison of clinical characteristics and outcomes in patients with left bundle branch block versus ST-elevation myocardial infarction referred for primary percutaneous coronary intervention.

AIMS: Recent studies have suggested that a low proportion of patients presenting with left bundle branch block (LBBB) require emergency intervention. In this study, we have compared baseline clinical characteristics, angiographic findings and subsequent outcomes in patients with LBBB versus ST-elevation myocardial infarction (STEMI) referred to our tertiary centre for primary percutaneous coronary intervention (PCI). METHODS AND RESULTS: A large retrospective observational study was performed involving 1875 consecutive patients presenting to our single tertiary cardiac centre for primary PCI over a 27-month period. Patients presenting with LBBB (n=155, 8.3%) were significantly older (P<0.0001) and were more likely to be female (P<0.0001) and have a prior history of myocardial infarction (P<0.0001) or coronary artery bypass graft surgery (P=0.005). Rates of acute occlusion (12.2 vs. 63%; P<0.0001) and PCI (26 vs. 83%; P<0.0001) were significantly lower in LBBB patients compared with STEMI patients. Although the 30-day mortality was similar, overall mortality during the 2 years of follow-up was significantly higher in the LBBB group compared with the STEMI group (27.8 vs. 13.9%; P=0.023). CONCLUSION: The incidence of an acutely occluded vessel is low in LBBB when compared with STEMI, but the long-term outcome is significantly worse. Patients with LBBB referred for primary PCI need better risk stratification, and further work is needed to identify potential diagnostic and management strategies.

Mineralocorticoid receptor antagonist pretreatment to MINIMISE reperfusion injury after ST-elevation myocardial infarction (the MINIMISE STEMI Trial): rationale and study design.

Novel therapies capable of reducing myocardial infarct (MI) size when administered prior to reperfusion are required to prevent the onset of heart failure in ST-segment elevation myocardial infarction (STEMI) patients treated by primary percutaneous coronary intervention (PPCI). Experimental animal studies have demonstrated that mineralocorticoid receptor antagonist (MRA) therapy administered prior to reperfusion can reduce MI size, and MRA therapy prevents adverse left ventricular (LV) remodeling in post-MI patients with LV impairment. With these 2 benefits in mind, we hypothesize that initiating MRA therapy prior to PPCI, followed by 3 months of oral MRA therapy, will reduce MI size and prevent adverse LV remodeling in STEMI patients. The MINIMISE-STEMI trial is a prospective, randomized, double-blind, placebo-controlled trial that will recruit 150 STEMI patients from four centers in the United Kingdom. Patients will be randomized to receive either an intravenous bolus of MRA therapy (potassium canrenoate 200 mg) or matching placebo prior to PPCI, followed by oral spironolactone 50 mg once daily or matching placebo for 3 months. A cardiac magnetic resonance imaging scan will be performed within 1 week of PPCI and repeated at 3 months to assess MI size and LV remodeling. Enzymatic MI size will be estimated by the 48-hour area-under-the-curve serum cardiac enzymes. The primary endpoint of the study will be MI size on the 3-month cardiac magnetic resonance imaging scan. The MINIMISE STEMI trial will investigate whether early MRA therapy, initiated prior to reperfusion, can reduce MI size and prevent adverse post-MI LV remodeling.

Typical takotsubo cardiomyopathy in suspected ST elevation myocardial infarction patients admitted for primary percutaneous coronary intervention.

AIM: Takotsubo cardiomyopathy (TCM) is increasingly being recognised in patients admitted with suspected acute coronary syndrome, as access to angiography and echocardiography is much quicker than before. We aimed to analyse the prevalence of typical TCM in patients admitted for primary percutaneous coronary intervention (PPCI) with suspected ST elevation myocardial infarction (STEMI) to a single tertiary centre in United Kingdom. METHODS: All patients admitted to our unit with suspected STEMI from September 2009 to November 2011 were included for analysis. RESULTS: Of the 1875 patients admitted, 17 patients (all female) with mean age of 69±11.9 yrs were identified to have clinical features of typical TCM, thus giving an overall prevalence of 0.9% in PPCI admissions (3.2% prevalence in women). The admission ECG showed ST elevation in 14 patients (82%) and 3 had LBBB (18%). In the 16 patients who had raised hs Troponin (normal range <14), the mean level was 921±668 (median 778, range 110 to 2550) ng/L. Two patients survived cardiac arrest and one had apical thrombus on presentation. Left ventricular function was severely impaired (EF ≤30%) in 2 patients, whilst it was moderately impaired (EF 31-50%) in others. During a mean follow-up period of 22±7 months (range 8-36 months), there was no mortality or recurrence. CONCLUSION: This is the first observational study to report the prevalence of typical TCM in patients admitted for PPCI in "real-world" practice. Though this condition is not benign during the acute episode, there is a good survival outcome if managed appropriately during the acute phase.

Should primary percutaneous coronary intervention be the routine reperfusion strategy in octogenarians presenting with ST elevation myocardial infarction?

AIM: Very few randomized trials have analysed the outcome of primary percutaneous coronary intervention (PPCI) for ST elevation myocardial infarction (STEMI) in very elderly patients (≥80 years). An observational study was performed to evaluate the outcome of PPCI in patients of at least 80 years of age who were admitted to our unit. METHODS: We included all patients undergoing PPCI in our unit from September 2009 to November 2011. RESULTS: Of the 1471 patients who underwent PPCI during the study period, 236 (16%) were at least 80 years of age. The mean age was 85 ±â€Š4 years (range 80-99 years, median 85 years). There was a significant difference in in-hospital mortality [14.4 vs. 2.9%, odds ratio (OR) 5.6, 95% confidence interval (CI) 3.4-9.2, P <0.0001], 30-day mortality (20.3 vs. 4%, OR 6.2, 95% CI 4.0-9.5, P <0.0001), 1-year mortality (28.8 vs. 6.2%, OR 6.1, 95% CI 4.2-8.8, P <0.0001), 30-day stent thrombosis (1.7 vs. 0.4%, OR 4.2, 95% CI 1.1-15.9, P = 0.04) and non-coronary artery bypass grafting major bleed (5.9 vs. 3%, OR 2, 95% CI 1.1-3.8, P = 0.03) between patients aged at least 80 years and those less than 80 years. CONCLUSION: The mortality in our patients of at least 80 years was similar to the previously published data, despite the advances in PPCI procedures. Considering the increasing number of octogenarian patients with STEMI at the present time, there is a need for a randomized trial to compare the different treatment strategies for STEMI.

Impact of a chronic total occlusion in a non-infarct related artery on clinical outcomes following primary percutaneous intervention in acute ST-elevation myocardial infarction.

AIMS: We aimed to assess the impact of a non-infarct related artery (IRA) chronic total occlusion (CTO) on clinical outcomes following primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI) in a real-world cohort of patients. METHODS AND RESULTS: This is a retrospective observational study of 1435 patients treated at a large single tertiary cardiac center providing a high-volume PPCI service. Patients with coexisting CTO (4.7%) were significantly more likely to have presented in cardiogenic shock and less likely to achieve TIMI 2/3 flow in the IRA post procedure resulting in lower ejection fraction and higher peak troponin-T levels. A concurrent CTO in a non-IRA was associated with higher in-hospital mortality (16.4% vs 3.1%; P<.001), 30-day mortality (19.4% vs 5.9%; P<.001) and long-term mortality (23.9% vs 12.2%; P=.01). Binary logistic regression analysis showed that the presence of a non-IRA CTO was independently predictive of mortality at 30 days (odds ratio, 3.2; 95% confidence interval, 1.2-8.1) but not for long-term mortality. CONCLUSION: The presence of a coexisting CTO in patients undergoing PPCI for STEMI is associated with adverse clinical outcomes; further work is required to improve prognosis in these patients, which may include early staged revascularization of the non-IRA CTO.

Rotational Atherectomy in a Patient with Acute ST-Elevation Myocardial Infarction and Cardiogenic Shock.

Rotational atherectomy (rotablation) of coronary artery is relatively contraindicated in high thrombotic state such as acute ST-elevation myocardial infarction (STEMI) because of the risk of platelet activation by the rotablator. We present a case where rotablation was necessary to recanalize the right coronary artery in a patient presenting with acute STEMI complicated by cardiogenic shock, after unsuccessful attempts with balloon catheters. He improved remarkably after the procedure and was discharged after 4 days.

The advantages of a consultant led primary percutaneous coronary intervention service on patient outcome.

BACKGROUND: Mortality among emergency medical admissions has been reported to be higher when patients are admitted to hospital at nights and weekends. AIM: We studied the outcome of ST elevation myocardial infarction (STEMI) patients presenting at different times to our centre with 24/7 primary percutaneous coronary intervention (PPCI) service. METHODS: We divided all patients who underwent PPCI between September 2009 and November 2011 into three groups according to the time of admission as group 1: in-hours (0800-1800 h weekdays), group 2: out-of-hours (1800- 0800 h weekdays) and group 3: weekends (Sat to Mon 0800-0800 h). RESULTS: A total of 605 (41.1%), 397 (27%) and 469 (31.9%) were included in group 1, 2 and 3, respectively. Apart from cardiogenic shock (8.9%, 5.5% and 7.7%, P = 0.05) and door to balloon time (median 29, 33 and 36 min, P < 0.0001), there was no significant difference noted in the baseline and procedural characteristics between the groups. In-hospital mortality (4.6%, 4.3% and 5.3%, P = 0.5), 30-day mortality (6.4%, 6.3% and 7%, P = 0.7), 30-day stent thrombosis (0.8%, 0.8% and 0.2%, P = 0.1) and 1-year mortality (10.7%, 10.8% and 9.8%, P = 0.7) were no difference between the groups. On logistic regression analysis, out-of-hours and weekend admissions were not found to be a predictor of both 30-day and 1-year mortality. CONCLUSION: In this consecutive series of patients admitted to a high volume PPCI centre, there was no difference in mortality when patients were admitted at different times. The involvement of senior medical staff early in the patients' admission may have contributed to these consistent outcomes.

Comparison of bivalirudin with heparin versus abciximab with heparin for primary percutaneous coronary intervention in "Real World" practice.

OBJECTIVE: We aimed to carry out a "real world" comparison of bivalirudin plus unfractionated heparin (UFH) versus abciximab plus UFH in patients undergoing primary percutaneous coronary intervention (PPCI) for ST elevation myocardial infarction (STEMI). METHODS: We included patients who had abciximab or bivalirudin during their PPCI in our unit between Sept 2009 and Nov 2011. RESULTS: The study included 516 and 484 patients in the bivalirudin and abciximab group respectively. There were more women in the bivalirudin group (29% vs 20%, p 0.001), while cardiogenic shock (6.4% vs 10.1%, p 0.04) and thrombectomy device use (76.6% vs 82%, p 0.04) were lower in the bivalirudin group. The primary composite end point of 30-day mortality, 30-day definite stent thrombosis or non-CABG major bleeding was similar between the bivalirudin and abciximab groups (7.8% vs 9.5%, OR 0.8, 95% CI 0.5 to 1.2, p 0.4). There was also no difference in in-hospital mortality (4.1% vs 4.3%, p 0.9), 30-day mortality (5.2% vs 6.4%, p 0.5), 1-year mortality (9.1% vs 9.9%, p 0.7), 30-day stent thrombosis (1% vs 0.4%, p 0.5) and non-CABG bleeding (2.7 vs 3.7%, p 0.4) between the bivalirudin and abciximab group respectively. On Cox proportional hazard analysis after adjusting for all the co-variates, the use of bivalirudin was not a predictor of 30-day mortality (HR 1.13, 95% CI 0.7-1.9, p 0.7). CONCLUSION: In this "real-world" observational study, there was no significant difference in the clinical outcome of PPCI for patients who had abciximab or bivalirudin after initial pre-treatment with UFH.