Reperfusion Strategies and Outcomes of ST-Segment Elevation Myocardial Infarction Patients in Canada: Observations From the Global Registry of Acute Coronary Events (GRACE) and the Canadian Registry of Acute Coronary Events (CANRACE)

Increased Cystatin C Level in ST-Elevation Myocardial Infarction Predisposes the Prognosis of Angioplasty

BACKGROUND

The study aimed to evaluate the prognostic value of cystatin C in ST-elevation acute myocardial infarction (STEMI) patients who underwent elective percutaneous coronary intervention (PCI).

METHODS

A retrospective study was conducted on 664 STEMI patients from 7 centers who were treated with elective PCI. These patients were divided into 3 groups according their admission cystatin C levels as < 0.84, 0.84-1.03 and ≥1.04mg/L. The all-cause mortalities and the composite endpoints, including mortality, reinfarction, rehospitalization for heart failure and angina or repeat target vessel revascularization were observed for up to 5 years.

RESULTS

As cystatin C levels from low to high, all-cause mortalities were progressively increased 0.9%, 3.7% and 9.5% (P < 0.001), as well as the composite endpoints, 11.1%, 21.7% and 40.7%, respectively (P < 0.001). When patients had the level of cystatin C ≥0.84mg/L, their risks of composite endpoints increased 2- to 3-fold of those with <0.84mg/L, with the adjusted hazard ratio of 2.096 (95% CI: 1.047-4.196, P = 0.037) and 3.608 (95% CI: 1.939-6.716, P < 0.001), respectively.

CONCLUSIONS

Increased cystatin C levels may be associated with enhanced risks of composite endpoints in patients with STEMI undergoing elective PCI.

Correlation of triglycerides with myocardial infarction and analysis of risk factors for myocardial infarction in patients with elevated triglyceride

Background

This study aims to investigate the associations of different (low/medium/high) levels of fasting triglyceride (TG) levels with cardiovascular endpoints.

Methods

This cohort study comprised of in-service and retired employees of the Kailuan Coal Mine Group, who participated in the health examination conducted in 11 hospitals in the Kailuan region from June 2006 to October 2007 (n=100,271). The study population was divided into five groups according to different TG levels. Logistic regression analysis was used to analyze the risk factors for myocardial infarction (MI) in patients with elevated TG, and Cox proportional hazards regression analysis was used to analyze the effects of different TG levels on endpoint events.

Results

After a median follow-up of 7 years, 961 patients developed MI and 3,142 subjects died. The multivariate logistic regression analysis revealed that elevated TG, an age of ≥65 years old, body mass index (BMI) >25 kg/m², fasting blood glucose (FBG) ≥6.1 mmol/L and high density lipoprotein cholesterol (HDL-C) <1.5 mmol/L were all risk factors for MI (P<0.05). Furthermore, Cox proportional hazards regression model revealed that after controlling for gender, age and other factors, with the increase in TG level, the relative risk of MI also increased. Compared to the TG1 group, the risk of MI increased to 1.32 folds in the TG4 group (95% CI: 1.05-1.66, P=0.018) and 1.61 folds in the TG5 group (95% CI: 1.21-1.93, P=0.004). Furthermore, the risk of MI combined with all-cause death and all-cause death also increased, but the differences were not all statistically significant.

Conclusions

In the study population of the Kailuan region, elevated fasting TG increases the risk of MI, particularly in populations with an age of ≥65 years old, BMI >25 kg/m², FBG ≥6.1 mmol/L and HDL-C <1.5 mmol/L.

Management Strategies and Outcomes of ST-Segment Elevation Myocardial Infarction Patients Transferred After Receiving Fibrinolytic Therapy in the United States

Fibrinolytic therapy is still used in patients with ST-segment elevation myocardial infarction (STEMI) when the primary percutaneous coronary intervention cannot be provided in a timely fashion. Management strategies and outcomes in transferred fibrinolytic-treated STEMI patients have not been well assessed in real-world settings. Using the Nationwide Inpatient Sample from 2008 to 2012, we identified 18 814 patients with STEMI who received fibrinolytic therapy and were transferred to a different facility within 24 hours. The primary outcome was in-hospital mortality. Secondary outcomes included gastrointestinal bleeding, bleeding requiring transfusion, intracranial hemorrhage (ICH), length of stay, and cost. The patients were divided into 3 groups: those who received medical therapy alone (n = 853; 4.5%), those who underwent coronary artery angiography without revascularization (n = 2573; 13.7%), and those who underwent coronary artery angiography with revascularization (n = 15 388; 81.8%). Rates of in-hospital mortality among the groups were 20% vs 6.6% vs 2.1%, respectively (P < 0.001); ICH was 8.5% vs 1.1% vs 0.6%, respectively (P < 0.001); and gastrointestinal bleeding was 1.1% vs 0.4% vs 0.4%, respectively (P = 0.011). Multivariate analysis identified increasing age, higher Charlson Comorbidity Index score, cardiogenic shock, cardiac arrest, and ICH as the independent predictors of not performing coronary artery angiography and/or revascularization in patients with STEMI initially treated with fibrinolytic therapy. The majority of STEMI patients transferred after receiving fibrinolytic therapy undergo coronary angiography. However, notable numbers of patients do not receive revascularization, especially patients with cardiogenic shock and following a cardiac arrest.

Evaluating clinical reason and rationale for not delivering reperfusion therapy in ST elevation myocardial infarction patients: Insights from a comprehensive cohort

BACKGROUND

In ST elevation myocardial infarction (STEMI), reperfusion therapy is lifesaving but is not delivered in approximately one quarter of patients. To address this care gap, we reviewed all STEMI patients that did not receive reperfusion to identify patient characteristics, in-hospital outcomes and the clinical reason or rationale for withholding reperfusion therapy.

METHODS

A prospective chart review identified a consecutive cohort of STEMI patients over one-year within a defined health care region with independent data abstraction. Subsequently a trained nurse completed retrospective chart review and categorized patients by rationale for failure to receive reperfusion.

RESULTS

Of 745 STEMI patients, 181 (24.3%) did not receive reperfusion. Compared to those receiving reperfusion, they were older (67.5 vs. 58.0years, p=0.001) with more comorbidities and higher in-hospital mortality (15.5% vs. 3.5% p=<0.0001). After excluding 35 patients (unavailable data) there were 146 STEMI patients for qualitative determination. Patient delay greater than 12hours from symptom onset accounted for the majority of patients (56/146, 38.4%). In 19.9% (29/146), conservative medical management with documented rationale occurred. Following angiography, primary PCI was attempted but was unsuccessful or no culprit lesion identified in 19.2% (28/146). The diagnosis of STEMI was missed or no rationale for failure to deliver therapy identified in 8.2% (12/146). Death prior to planned reperfusion occurred in 8 (8/146, 5.5%).

CONCLUSIONS

Legitimate rationale exists for the majority of STEMI patients not receiving reperfusion. Ultimately, only 1.6% (12/745) of consecutive STEMI patients failed to receive reperfusion without documented rationale or due to missed diagnosis.

Effect of coronary artery revascularization on in-hospital outcomes and long-term prognoses in acute myocardial infarction patients with prior ischemic stroke

Objective

To investigate whether coronary artery revascularization therapies (CART), including percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), can improve the in-hospital and long-term outcomes for acute myocardial infarction (AMI) patients with prior ischemic stroke (IS).

Methods

A total of 387 AMI patients with prior IS were enrolled consecutively from January 15, 2005 to December 24, 2011 in this cohort study. All patients were categorized into the CART group (n = 204) or the conservative medications (CM) group (n = 183). In-hospital cardiocerebral events and long-term mortality of the two groups after an average follow-up of 36 months were recorded by Kaplan-Meier survival curves and compared by Logistic regression and the Cox regression model.

Results

The CART patients were younger (66.5 ± 9.7 years vs. 71.7 ± 9.7 years, P < 0.01), had less non-ST segment elevation myocardial infarction (11.8% vs. 20.8%, P = 0.016) and more multiple-vascular coronary lesions (50% vs. 69.4%, P = 0.031). The hospitalization incidence of cardiocerebral events in the CART group was 9.3% while 26.2% in the CM group (P < 0.01). CART significantly reduced the risk of in-hospital cardiocerebral events by 65% [adjusted odds ratio (OR) = 0.35, 95% CI: 0.13–0.92]. By the end of follow-up, 57 cases (41.6%) died in CM group (n = 137) and 24 cases (12.2%) died in CART group (n = 197). Cox regression indicated that CART decreased the long-term mortality by 72% [adjusted hazard ratio (HR) = 0.28, 95% CI: 0.06–0.46], while categorical analysis indicated no significant difference between PCI and CABG.

Conclusions

CART has a significant effect on improving the in-hospital and long-term prognoses for AMI patients with prior IS.

A Novel Approach to Improve Time to First Shock in Prehospital STEMI Complicated by Ventricular Fibrillation

Lethal cardiac arrhythmias such as ventricular fibrillation and pulseless ventricular tachycardia (VF/pVT) complicate up to 6% of all out-of-hospital STEMIs. Typically, paramedics respond to this by applying defibrillation pads and delivering a shock as soon as possible. A recently introduced "pads-on" protocol directed paramedics to apply defibrillation pads to all STEMI patients (regardless of clinical stability) with the aim of decreasing time to first shock. In this article we present two cases of prehospital STEMI complicated by VF to illustrate times to first shock for the two different protocols. One case each of a STEMI complicated by VF before implementation of the pads-on protocol and after the implementation of the protocol is presented. An important difference in the time to first shock is noted between the two patients with STEMI complicated by VF. While it took 2 min 43 s for the pads-off patient to be defibrillated, only 27 s elapsed before the pads-on patient was defibrillated. These two cases demonstrate that the application of defibrillation pads immediately following the diagnosis of prehospital STEMI has the potential to decrease the time to shock in patients suffering VF/pVT.

Efficacy of an early invasive strategy after fibrinolysis in ST-elevation myocardial infarction relative to the extent of coronary artery disease

BACKGROUND

A strategy of early transfer for coronary angiography and intervention is superior to a standard approach of delayed coronary angiography after fibrinolysis for ST-elevation myocardial infarction (STEMI). STEMI patients with lesions in noninfarct-related arteries have a worse prognosis compared with patients with single vessel disease. This study aimed to assess whether the benefits of an early invasive strategy differ in patients with single vessel and multivessel disease.

METHODS

The Trial of Routine ANgioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI) randomized STEMI patients receiving fibrinolysis to a strategy of early transfer and coronary angiography vs a standard approach. In this post hoc analysis, we stratified 992 patients into 2 groups according to the presence or absence of multivessel disease. We compared the 2 groups in terms of baseline characteristics, in-hospital management, and patient outcomes, and tested for treatment heterogeneity.

RESULTS

Multivessel disease was present in 369 (37%) patients. Patients with multivessel disease had a greater rate of the primary composite end point of in-hospital death, recurrence of infarction, recurrent ischemia, shock, or heart failure at 30 days (18.2% vs 10.8%; P < 0.001). An early invasive strategy was efficacious in both groups for the primary outcome. In multivariable analysis adjusting for Global Registry of Acute Coronary Events (GRACE) risk score, there was no significant treatment heterogeneity (all P interaction > 0.40) for the primary end point, or death/recurrence of infarction at 6 months and 1 year.

CONCLUSIONS

Multivessel disease is present in a significant proportion of STEMI patients treated with fibrinolysis and is associated with worse outcomes. A strategy of early transfer and coronary intervention after fibrinolysis was beneficial regardless of the presence or absence of multivessel disease.

Early and late outcomes after primary percutaneous coronary intervention by radial or femoral approach in patients presenting in acute ST-elevation myocardial infarction and cardiogenic shock

BACKGROUND

Although radial approach is increasingly used in percutaneous coronary interventions (PCIs) including in acute myocardial infarction (MI), patients with cardiogenic shock have been excluded from comparisons with femoral approach. The aim of our study was to compare clinical outcomes in patients undergoing primary PCI with cardiogenic shock by radial and femoral approach.

METHODS AND RESULTS

From 2,663 patients presenting with ST-elevation MI in 2 large volume radial centers, we identified 197 patients (7.4%) with signs of cardiogenic shock immediately before undergoing primary PCI. Radial approach was used in 55% of cases when at least 1 radial artery was weakly palpable, either spontaneously or after intravenous noradrenaline bolus. Patients in the radial group were older (69 ± 12 vs 64 ± 12 years, P = .010), had less diabetes (13% vs 26%, P = .028), and required less often intubation prior PCI (42% vs 66%, P = .0006) or intraaortic balloon pump (36% vs 55%, P = .0096). Mortality at 1 year was 44% in the radial group and 64% in the femoral group (P = .0044). Independent predictors of late mortality included radial approach (hazard ratio [HR] 0.65, 95% CI 0.42-0.98, P = .041), the use of glycoprotein IIb-IIIa receptor inhibitors (HR 0.63, 95% CI 0.40-0.96, P = .032), baseline creatinine ≥110 μmol/L (HR 3.34, 95% CI 2.20-5.12, P < .0001), initial glycemia >200 mg/dL (HR 2.02, 95% CI 1.34-3.11, P = .0008), and age >65 years (HR 1.80, 95% CI 1.18-2.79, P = .006).

CONCLUSION

Radial approach was safe and feasible in more than half of the patients with ST-elevation MI and cardiogenic shock treated by primary PCI. After adjustment for baseline and procedural characteristics, radial approach remained associated with better survival. However, prognosis of patients undergoing primary PCI in cardiogenic shock remains poor.

Efficacy of early invasive management post-fibrinolysis in men versus women with ST-elevation myocardial infarction: a subgroup analysis from Trial of Routine Angioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI)

BACKGROUND

The TRANSFER-AMI study demonstrated that early routine percutaneous coronary intervention post-fibrinolysis (pharmacoinvasive strategy) is superior to conservative management for ST-elevation myocardial infarction. However, it is not clear whether treatment efficacy differs between men and women.

METHODS

In this pre-specified subgroup analysis, we compared the efficacy of a pharmacoinvasive strategy in men versus women with acute ST-elevation myocardial infarction who were randomized to a pharmacoinvasive versus standard management following fibrinolysis. The primary end point was a composite of death, recurrent myocardial infarction, recurrent ischemia, heart failure and shock at 30 days. We tested for treatment heterogeneity between men and women using the Breslow-Day test. We also performed multivariable analysis adjusting for GRACE risk score and its interaction with treatment assignment, and evaluated for death/recurrent myocardial reinfarction as a secondary outcome.

RESULTS

Of the 1059 patients, 843 were men and 216 were women. Compared to men, women were older, had worse Killip class, higher GRACE risk score, and higher rates of death and death/myocardial reinfarction at 30 days. The primary end point did not differ significantly between men and women (13.4% vs 16.7%, P = .22). Compared to standard treatment, a pharmacoinvasive strategy was associated with a lower rate of the primary end point in men (17.5% vs 9.4%, respectively, P < .001), but not in women (16.2% vs 17.1%, P = .86). There was a trend toward an interaction between treatment assignment and sex for the composite primary end point (P = .06). After adjustment for the significant interaction between GRACE risk score and treatment (P < .001), there was no significant interaction between sex and treatment for all the end points (all P > .40).

CONCLUSION

The borderline heterogeneity in treatment efficacy of a pharmacoinvasive strategy in men versus women was no longer evident after adjustment for the difference in baseline risk. This suggests that sex per se was not an important determinant of the efficacy of a pharmacoinvasive strategy. Owing to the small number of women in this trial, further study in this area is needed.