Comparison of angiographic and other findings and mortality in non-ST-segment elevation versus ST-segment elevation myocardial infarction in patients undergoing early invasive intervention

Postdilatation after stent deployment during primary percutaneous coronary intervention: a systematic review and meta-analysis

BACKGROUND

The utilization of postdilatation in primary percutaneous coronary intervention (PCI) is feared to induce suboptimal coronary blood flow and compromise the outcome of the patients. This meta-analysis sought to verify whether postdilatation during primary PCI is associated with worse angiographic or long-term clinical outcomes.

METHODS

Systematic literature searches were conducted on PubMed, The Cochrane Library, ClinicalTrials.gov, EBSCO, and Europe PMC on 10 March 2024. Eligible studies reporting the outcomes of postdilatation among ST-segment elevation myocardial infarction patients were included. The primary outcome was no-reflow condition during primary PCI based on angiographic finding. The secondary clinical outcome was major adverse cardiovascular events (MACEs) comprising all-cause death, myocardial infarction, target vessel revascularization (TVR), and stent thrombosis.

RESULTS

Ten studies were finally included in this meta-analysis encompassing 3280 patients, which was predominantly male (76.6%). Postdilatation was performed in 40.7% cases. Postdilatation was associated with increased risk of no-reflow during primary PCI [Odd Ratio (OR) = 1.33, 95% Confidence Interval (CI): 1.12-1.58; P = .001)]. Conversely, postdilatation had a tendency to reduce MACE (OR = 0.70, 95% CI: 0.51-0.97; P = .03) specifically in terms of TVR (OR = 0.41, 95% CI: 0.22-0.74; P = .003). No significant differences between both groups in relation to mortality (OR = 0.58, 95% CI: 0.32-1.05; P = .07) and myocardial infarction (OR = 1.5, 95% CI: 0.78-2.89; P = .22).

CONCLUSIONS

Postdilatation after stent deployment during primary PCI appears to be associated with an increased risk of no-reflow phenomenon after the procedure. Nevertheless, postdilatation strategy has demonstrated a significant reduction in MACE over the course of long-term follow-up. Specifically, postdilatation significantly decreased the occurrence of TVR. Key messages: What is already known on this topic?  Optimizing stent deployment by performing postdilatation during percutaneous coronary intervention (PCI) is essential for long-term clinical outcomes. However, its application during primary PCI is controversial due to the fact that it may provoke distal embolization and worsen coronary blood flow. What this study adds?  In this systematic review and meta-analysis of 10 studies, we confirm that postdilatation during primary PCI is associated with worse coronary blood flow immediately following the procedure. On the contrary, this intervention proves advantageous in improving long-term clinical outcomes, particularly in reducing target vessel revascularization. How this study might affect research, practice, or policy?  Given the mixed impact of postdilatation during primary PCI, this strategy should only be applied selectively. Future research should focus on identifying patients who may benefit from such strategy.

Sex-based Differences in Percutaneous Coronary Intervention Outcomes in Patients With Ischemic Heart Disease

In high-income countries, ischaemic heart disease is the leading cause of death in women and men, accounting for more than 20% of deaths in both sexes. However, women are less likely to receive guideline-recommended percutaneous coronary intervention (PCI) than men. Women undergoing PCI have poorer unadjusted outcomes because they are older and have greater comorbidity than men, but uncertainty remains whether sex affects outcome after these differences in clinical characteristics are considered. In this paper, we review recent published evidence comparing outcomes between men and women undergoing PCI. We focus on the sex differences in PCI outcomes in different scenarios: acute coronary syndromes, stable angina and complex lesions, including the approach of left main coronary artery. We also review how gender is considered in recent guidelines and offer a common clinical scenario to illustrate the contemporary management strategies an interventional cardiologist should consider when performing PCI on a female patient.

High-dose statin pretreatment decreases periprocedural myocardial infarction and cardiovascular events in East Asian patients undergoing percutaneous coronary intervention: A meta-analysis of fifteen randomized controlled trials

BACKGROUND

Numerous studies have shown that high-dose statin pretreatment may reduce the risk of periprocedural myocardial infarction (PMI) and short-term major adverse cardiac events (MACE) in western people undergoing percutaneous coronary intervention (PCI). However, the effects in East Asian patients are still controversial. The objective was to evaluate the effects of short-term high-dose statin (all types) pretreatment compared with the control (low-dose or no statin) on the reduction of the rate of MACE and PMI in East Asian patients.

METHODS

PubMed/Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically searched for randomized controlled trials (RCTs) in East Asian patients up to December 2019, in which short-term high-dose statin pretreatment was compared with control for patients undergoing PCI. The primary outcome measure was the incidence of MACE at 30 days. The secondary outcome measure was the incidence of PMI. The meta-analysis was performed with the fixed-effect model or random-effects model according to the heterogeneity. The meta-analysis was performed using RevMan 5.3 software (Cochrane Collaboration).

RESULTS

Fifteen RCTs that enrolled 4313 East Asian patients were identified. High-dose statin pretreatment was associated with a 54% relative reduction in 30-day MACE (OR, 0.46; 95% CI, 0.31-0.67; P < .001) and a 50% relative reduction in PMI (OR, 0.50; 95% CI, 0.34-0.76; P = .001).

CONCLUSIONS

High-dose statin pretreatment can significantly reduce 30-day MACE and PMI for East Asian patients undergoing PCI.

Effects of Prolonged Dual Antiplatelet Therapy in ST-Segment Elevation vs. Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

The benefits and risks of prolonged dual antiplatelet therapy (DAPT) have not been studied extensively across a broad spectrum of acute coronary syndromes. In this study we investigated whether treatment effects of prolonged DAPT were consistent in patients presenting with ST-segment elevation myocardial infarction (STEMI) vs. non-STEMI (NSTEMI).

METHODS AND RESULTS

As a post hoc analysis of the SMART-DATE trial, effects of ≥12 vs. 6 months DAPT were compared among 1,023 patients presenting with STEMI and 853 NSTEMI patients. The primary outcome was a composite of recurrent myocardial infarction (MI) or stent thrombosis at 18 months after the index procedure. Compared with the 6-month DAPT group, the rate of the composite endpoint was significantly lower in the ≥12-month DAPT group (1.2% vs. 3.8%; hazard ratio [HR] 0.31, 95% confidence interval [CI] 0.12-0.77; P=0.012). The treatment effect of ≥12- vs. 6-month DAPT on the composite endpoint was consistent among NSTEMI patients (0.2% vs. 1.2%, respectively; HR 0.20, 95% CI 0.02-1.70; P=0.140; Pinteraction=0.718). In addition, ≥12-month DAPT increased Bleeding Academic Research Consortium (BARC) Type 2-5 bleeding among both STEMI (4.4% vs. 2.0%; HR 2.18, 95% CI 1.03-4.60; P=0.041) and NSTEMI (5.1% vs. 2.2%; HR 2.37, 95% CI 1.08-5.17; P=0.031; Pinteraction=0.885) patients.

CONCLUSIONS

Compared with 6-month DAPT, ≥12-month DAPT reduced recurrent MI or stent thrombosis regardless of the type of MI at presentation.

Comparison of the cost in percutaneous coronary intervention between ST-segment elevation myocardial infarction vs. non-ST-segment elevation myocardial infarction

Percutaneous coronary intervention (PCI) is a standard strategy for non-ST-segment elevation myocardial infarction (NSTEMI) as well as for ST-segment elevation myocardial infarction (STEMI). The device cost for PCI may be more expensive in NSTEMI, because the culprit lesion morphology may be more complex in NSTEMI. This study aimed to compare the total device cost of PCI between STEMI and NSTEMI. We included 504 patients with acute myocardial infraction (AMI) who underwent PCI, and divided those into a STEMI group (n = 286) and a NSTEMI group (n = 218). We compared the total device cost, the number of used devices, and procedure cost between the 2 groups. The total device cost was significantly higher in the NSTEMI group [¥371,300 (¥320,700-503,350)] than in the STEMI group [¥341,200 (¥314,200-410,475)] (p = 0.001), whereas the procedure cost was significantly higher in the STEMI group [¥343,800 (¥243,800-343,800)] than in the NSTEMI group [¥220,000 (¥216,800-243,800)] (p < 0.001). Drug eluting stent (85.3% vs. 76.1%, p = 0.029) and aspiration catheter (16.8% vs. 2.3%, p < 0.001) were more frequently used in the STEMI group, whereas rotablator (0.7% vs. 8.3%, p < 0.001) were more frequently used in the NSTEMI group. The multivariate logistic regression analysis revealed that NSTEMI was significantly associated with the high device cost (odds ratio 1.899, 95% confidence interval 1.166-3.093, p = 0.01). In conclusion, the total device cost for PCI was significantly higher in the culprit lesions of NSTEMI than in those of STEMI, whereas the procedure cost was significantly higher in the culprit lesions of STEMI than in those of NSTEMI.

Impact of electrocardiographic morphology on clinical outcomes in patients with non-ST elevation myocardial infarction receiving coronary angiography and intervention: a retrospective study

Background

The impact of electrocardiography (ECG) morphology on clinical outcomes in patients with non-ST segment elevation myocardial infarction (NSTEMI) receiving percutaneous coronary intervention (PCI) is unknown. This study investigated whether different ST morphologies had different clinical outcomes in patients with NSTEMI receiving PCI.

Methods

This retrospective study analyzed record-linked data of 362 patients who had received PCI for NSTEMI between January 2008 and December 2010. ECG revealed ST depression in 67 patients, inverted T wave in 91 patients, and no significant ST-T changes in 204 patients. The primary endpoint was long-term all-cause mortality. The secondary endpoint was long-term cardiac death and non-fatal major adverse cardiac events.

Results

Compared to those patients whose ECG showed an inverted T wave and non-specific ST-T changes, patients whose ECG showed ST depression had more diabetes mellitus, advanced chronic kidney disease (CKD) and left main artery disease, as well as more in-hospital mortality, cardiac death and pulmonary edema during hospitalization. Patients with ST depression had a significantly higher rate of long-term total mortality and cardiac death. Finally, multiple stepwise Cox regression analysis showed that an advanced Killip score, age, advanced CKD, prior percutaneous transluminal coronary angioplasty and ST depression were independent predictors of the primary endpoint.

Conclusions

Among NSTEMI patients undergoing coronary angiography, those with ST depression had more in-hospital mortality and cardiac death. Long-term follow-up of patients with ST depression consistently reveals poor outcomes.

Determinants of Slow Flow in Percutaneous Coronary Intervention to the Culprit Lesion of Non-ST Elevation Myocardial Infarction

Slow flow is a serious complication in percutaneous coronary intervention (PCI) and is associated with poor clinical outcomes. Our previous study revealed that the ratio of stent diameter to vessel diameter was the determinant of slow flow in intravascular ultrasound (IVUS)-guided PCI to the culprit lesion of ST elevation myocardial infarction (STEMI). The purpose of this study was to verify whether the ratio of stent diameter to vessel diameter is the determinant of slow flow in IVUS-guided PCI to the culprit lesion of non-STEMI (NSTEMI). We included 150 NSTEMI patients and divided into the slow flow group (n = 17) and the non-slow flow group (n = 133). The ratio of stent diameter to vessel diameter was significantly larger in the slow flow group (0.77 ± 0.11) than the non-slow flow group (0.71 ± 0.11) (P = 0.03). Multivariate logistic regression analysis revealed that the ratio of stent diameter to vessel diameter (per 0.1 increase: OR 2.06, 95% CI 1.23-3.46, P = 0.006) was the determinant of slow flow after controlling covariates. In conclusion, the ratio of stent diameter to vessel diameter was the determinant of slow flow in IVUS-guided PCI to the culprit lesion of NSTEMI. Unlike other parameters, the ratio of stent diameter to vessel diameter is the modifiable parameters. We may consider the modest stent expansion strategy rather than the aggressive stent expansion strategy in IVUS-guided PCI to the culprit lesion of NSTEMI.

Long-term outcomes of bypass grafting versus drug-eluting stenting for left main coronary artery disease: Results from the IRIS-MAIN registry

There are limited data on comparative outcomes and its determinants following coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) with drug-eluting stents (DES) for left main coronary artery disease (LMCAD) in a real-world setting.

METHODS

A total of 3,504 consecutive patients with LMCAD treated with CABG (n=1,301) or PCI with DES (n=2,203) from the IRIS-MAIN registry were analyzed. The relative treatment effect of one strategy over another was assessed by propensity-score matching method. The primary outcome was a composite of death, myocardial infarction, or stroke.

RESULTS

Median follow-up duration was 4.7 years. In the matched cohort, both groups demonstrated a similar risk for the primary outcome (adjusted hazard ratio [HR]: 0.94; 95% CI: 0.77-1.15; P=.54). Compared with CABG, PCI exhibited higher risks of myocardial infarction (HR: 2.11; 95% CI: 1.16-3.83; P=.01) and repeated revascularization (HR: 5.95; 95% CI: 3.94-8.98; P<.001). In the overall population, age, presence of chronic kidney disease, and low ejection fraction (<40%) were key clinical predictors of primary outcome regardless of the treatment strategy. However, factors deemed to be associated with perioperative morbidity were determinants of primary outcome in the CABG group, whereas those generally associated with the severity of atherosclerotic coronary artery disease were strong predictors in the PCI group.

CONCLUSIONS

Among patients with significant LMCAD, the long-term risk of the composite outcome of death, myocardial infarction, or stroke was similar between CABG and PCI. Clinical variables that differentially predict adverse outcomes might be useful in triaging appropriate revascularization strategy.

Outcome after percutaneous coronary intervention for different indications: long-term results from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

AIMS

The aim of this study was to evaluate clinical outcome for different indications for PCI in an unselected, nationwide PCI population at short- and long-term follow-up.

METHODS AND RESULTS

We evaluated clinical outcome up to six years after PCI in all patients undergoing a PCI procedure for different indications in Sweden between 2006 and 2010. A total of 70,479 patients were treated for stable coronary artery disease (CAD) (21.0%), unstable angina (11.0%), non-ST-elevation myocardial infarction (NSTEMI) (36.6%) and ST-elevation myocardial infarction (STEMI) (31.4%). Mortality was higher in STEMI patients at one year after PCI (9.6%) compared to NSTEMI (4.7%), unstable angina (2.2%) and stable CAD (2.0%). At one year after PCI until the end of follow-up, the adjusted mortality risk (one to six years after PCI) and the risk of myocardial infarction were comparable between NSTEMI and STEMI patients and lower in patients with unstable angina and stable CAD. The adjusted risk of stent thrombosis and heart failure was highest in STEMI patients.

CONCLUSIONS

The risk of short-term mortality, heart failure and stent thrombosis is highest for STEMI patients after PCI. Therapies to reduce stent thrombosis and heart failure appear to be most important in decreasing mortality in patients with STEMI or NSTEMI undergoing PCI.

Impact of chronic kidney disease on clinical outcomes in patients with non-ST elevation myocardial infarction receiving percutaneous coronary intervention - A five-year observational study

BACKGROUND

Patients with chronic kidney disease (CKD) experience poor outcomes after acute myocardial infarction. This study investigated how CKD affects clinical outcomes in patients with non-ST segment elevation myocardial infarction (NSTEMI) receiving PCI.

METHODS

This retrospective study analyzed record-linked data for 314 patients who had received PCI for NSTEMI between January 2008 and September 2010. The 141 patients with advanced CKD were compared with 173 patients who had mild or no CKD. The primary endpoint was long-term mortality. The secondary endpoint was long-term major adverse cardiac events.

RESULTS

Compared to the control group, the advanced CKD group had older patients, more females, and more patients with diabetes mellitus and hypertension. The advanced CKD group also had a lower left ventricular ejection fraction and more patients with advanced HF and pulmonary edema. The advanced CKD group and the control group did not significantly differ in total in-hospital mortality, cardiac death or temporary hemodialysis post-PCI. The advanced CKD group had a significantly higher rate of long-term events. Finally, multiple stepwise Cox regression analysis showed that old age, advanced CKD and advanced HF were independent predictors of primary endpoint. The best predictors of secondary endpoint were post-PCI Thrombolysis in Myocardial Infarction-3 flow, multiple vessel disease, advanced HF and advanced CKD.

CONCLUSIONS

In NSTEMI patients undergoing PCI, in-hospital mortality does not significantly differ between patients with and without advanced CKD. However, long-term follow up of CKD patients consistently reveals poor outcomes.

Meta-Analysis of Radial Versus Femoral Access for Percutaneous Coronary Interventions in Non-ST-Segment Elevation Acute Coronary Syndrome

Radial access for percutaneous coronary intervention (PCI) has been shown to reduce mortality and vascular complications compared to femoral access in patients with ST-segment elevation myocardial infarction. However, efficacy and safety of radial access PCI in non-ST-segment elevation acute coronary syndrome (NSTE ACS) is not well understood. A systematic search of electronic databases was performed through July 2015 to search and identify relevant studies. We evaluated the following short-term outcomes: all-cause mortality, major bleeding, access site bleeding, and need for blood transfusions. In addition, we evaluated 1-year mortality. Studies were pooled using random effects model. Nine studies including a total of 220,126 patients (radial approach: 94,663 patients [43%], femoral approach: 125,463 patients [57%]) were included in the analysis. On pooled analysis, no significant difference in incidence of short-term all-cause mortality was found between radial and femoral access (odds ratio [OR] 0.78, 95% CI 0.57 to 1.07, p = 0.12). Radial access was associated with significant reduction in major bleeding (OR 0.52, 95% CI 0.36 to 0.73, p = 0.0002), access-site bleeding (OR 0.41, 95% CI 0.22 to 0.78, p = 0.007), and need for blood transfusions (OR 0.61, 95% CI 0.41 to 0.91, p = 0.02). Furthermore, the 1-year mortality was significantly lower in radial approach (OR 0.72, 95% CI 0.55 to 0.95, p = 0.02). In conclusion, in patients with non-ST-segment elevation acute coronary syndrome undergoing PCI, radial access is associated with decreased bleeding and access-site complications.

The scientific achievements of the decades in Korean Acute Myocardial Infarction Registry

The Korea Acute Myocardial Infarction Registry (KAMIR) was the first nationwide registry data collection designed to track outcomes of patients with acute myocardial infarction (AMI). These studies reflect the current therapeutic approaches and management for AMI in Korea. The results of KAMIR could help clinicians to predict the prognosis of their patients and identify better diagnostic and treatment tools to improve the quality of care. The KAMIR score was proposed to be a predictor of the prognosis of AMI patients. Triple antiplatelet therapy, consisting of aspirin, clopidogrel and cilostazol, was effective at preventing major adverse clinical outcomes. Drug-eluting stents were effective and safe in AMI patients with no increased risk of stent thrombosis. Statin therapy was effective in Korean AMI patients, including those with very low levels of low density cholesterol. The present review summarizes the 10-year scientific achievements of KAMIR from admission to outpatient care during long-term clinical follow-up.

Spironolactone lowers the rate of repeat revascularization in acute myocardial infarction patients treated with percutaneous coronary intervention

BACKGROUND

We sought to assess the effect of the aldosterone receptor blocker, spironolactone, on 1-year clinical outcomes in all-comers with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention.

METHODS

A total of 10,309 AMI patients were recruited between November 2005 and April 2008 from a nationwide AMI registry in Korea. Patients were divided into 2 groups: those treated with spironolactone (n = 720; 7.0%) and those who had not been treated at discharge. The primary end point was major adverse cardiac events (MACEs), defined as the composite of death from any cause, recurrent AMI, or repeat revascularization at 1 year after admission.

RESULTS

The spironolactone group had a greater number of comorbidities than the nonspironolactone group. There was no significant association between the spironolactone treatment and MACE at 1 year (adjusted hazard ratio [HR] 0.95, 95% confidence interval 0.72-1.24, P = .69) in the overall population. The risks of death from any cause, cardiac death, and recurrent AMI were also similar between the groups. However, patients who received spironolactone had a lower risk of repeat revascularization than did those who did not receive spironolactone (adjusted HR 0.58, 95% CI 0.39-0.86, P = .007). Of guideline-eligible patients (n = 821/10,309; 8.0%), 170 (20.7%) of 821 patients received a spironolactone at hospital discharge. When limited to the guideline-eligible patients' population, a statistical trend toward lower MACE was observed in patients treated with spironolactone (14.3% vs 13.7%, adjusted HR 0.63, 95% CI 0.37-1.10, P = .10).

CONCLUSIONS

All-comer AMI patients undergoing percutaneous coronary intervention who received spironolactone had a lower risk of repeat revascularization. Randomized trials are needed.

Mean platelet volume predicts left descending artery occlusion in patients with non-ST-elevation myocardial infarction

Platelets play an important role in atherothrombosis. As the most common site plaque occurs, left anterior descending artery (LAD) infarct location always associate with poor prognosis. We sought to assess whether mean platelet volume (MPV) could predict LAD infarct location and short-term clinical outcome. In this study, 190 consecutive patients with non-ST-elevation myocardial infarction (NSTEMI) were enrolled. Clinical, electrocardiography and laboratory characteristics were measured. All patients underwent coronary angiography examination and had definite culprit vessel during hospitalization. The results showed that MPV was smaller in patients with a LAD infarct location than that of left circumflex artery or right coronary artery (9.0 ± 1.5 versus 9.8 ± 1.6, p<0.001). Multivariate analysis also showed that MPV was the only independent factor to predict LAD infarct location [Odds ratio (OR)=0.65, 95% confidence interval (CI) 0.53-0.80, p<0.0001] in patients with NSTEMI. B-type natriuretic peptide and electrocardiography were unreliable predictive factors to locate culprit vessel. Receiver operating characteristic curve analysis showed MPV (area under the curve: 0.65, 95% CI 0.56-0.74, p<0.01) could reliably discriminate those patients with NSTEMI who had a major in-hospital event. Multivariate regression analyses also showed that MPV (OR=1.46, 95% CI 1.15-1.86, p<0.01) were predictors of major in-hospital events. In conclusion, MPV was the only factor independently associated with LAD infarct location in patients with non-ST-elevation myocardial infarction.

Early- and late-term clinical outcome and their predictors in patients with ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction

BACKGROUNDS

The disparity between ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) remains controversial. We compared clinical outcomes and prognostic factors between STEMI and NSTEMI using large-scale registry data.

METHODS

We recruited 28,421 patients with STEMI (n=16,607) and NSTEMI (n=11,814) between November 2005 and April 2010 from a nationwide registry in Korea. We performed landmark analysis of cardiac death, recurrent acute myocardial infarction (re-AMI), revascularization, and major adverse cardiac events (MACE) at 30 days (early term) and 1 year (late term) after admission.

RESULTS

Patients with NSTEMI had a greater number of co-morbidities than STEMI patients. Early term MACE (6.9% vs. 4.5%, p<0.001) and cardiac death (6.1% vs. 3.7%, p<0.001) were higher in STEMI patients. However, late-term MACE (8.0% vs. 9.1%, p=0.007), cardiac death (1.9% vs. 2.6%, p=0.001), and re-AMI (0.6% vs. 1.3%, p<0.001) were lower in the STEMI group. The independent predictors of cardiac death were old age, renal dysfunction, LV dysfunction, Killip class, post-thrombolysis in myocardial infarction (TIMI) flow, and major bleeding in both groups. Female gender, previous ischemic heart disease, diabetes, current smoking, multivessel disease, and body mass index were MI type- or time-dependent predictors.

CONCLUSION

The STEMI group displayed poor early term clinical outcome, whereas the NSTEMI group displayed poor late-term clinical outcome. The STEMI and NSTEMI groups had different predictor profiles for cardiac death, suggesting that different strategies are required for improving the late-term outcome of STEMI and NSTEMI patients.

Type and timing of heralding in ST-elevation and non-ST-elevation myocardial infarction: an analysis of prospectively collected electronic healthcare records linked to the national registry of acute coronary syndromes

AIMS

It is widely thought that ST-elevation myocardial infarction (STEMI) is more likely to occur without warning (i.e. an unanticipated event in a previously healthy person) than non-ST-elevation myocardial infarction (NSTEMI), but no large study has evaluated this using prospectively collected data. The aim of this study was to compare the evolution of atherosclerotic disease and cardiovascular risk between people going on to experience STEMI and NSTEMI.

METHODS

We identified patients experiencing STEMI and NSTEMI in the national registry of myocardial infarction for England and Wales (Myocardial Ischaemia National Audit Project), for whom linked primary care records were available in the General Practice Research Database (as part of the CALIBER collaboration). We compared the prevalence and timing of atherosclerotic disease and major cardiovascular risk factors including smoking, hypertension, diabetes, and dyslipidaemia, between patients later experiencing STEMI to those experiencing NSTEMI.

RESULTS

A total of 8174 myocardial infarction patients were included (3780 STEMI, 4394 NSTEMI). Myocardial infarction without heralding by previously diagnosed atherosclerotic disease occurred in 71% STEMI (95% CI 69-72%) and 50% NSTEMI patients (95% CI 48-51%). The proportions of myocardial infarctions with no prior atherosclerotic disease, major risk factors, or chest pain was 14% (95% CI 13-16%) in STEMI and 9% (95% CI 9-10%) in NSTEMI. The rate of heralding coronary diagnoses was particularly high in the 12 months before infarct; 4.1-times higher (95% CI 3.3-5.0) in STEMI and 3.6-times higher (95% CI 3.1-4.2) in NSTEMI compared to the rate in earlier years.

CONCLUSIONS

Acute myocardial infarction occurring without prior diagnosed coronary, cerebrovascular, or peripheral arterial disease was common, especially for STEMI. However, there was a high prevalence of risk factors or symptoms in patients without previously diagnosed disease. Better understanding of the antecedents in the year before myocardial infarction is required.

Does clinical presentation affect outcome among patients with acute coronary syndromes undergoing percutaneous coronary intervention? Insights from the Providing Regional Observations to Study Predictors of Events in the Coronary Tree study

BACKGROUND

In some prior studies, patients with ST-elevation myocardial infarction (STEMI) as compared with patients with non-STEMI (NSTEMI) tended to have a higher early mortality but similar long-term outcomes. We compared the angiographic and intravascular ultrasound (IVUS) characteristics of patients with STEMI and NSTEMI in the PROSPECT study to evaluate the independent prognostic value of clinical presentation on long-term outcome.

METHODS

After successful revascularization, patients had 3-vessel quantitative coronary angiography, gray scale, and radiofrequency intravascular ultrasound (IVUS) imaging. The primary end point was the occurrence of major adverse cardiac events (MACE) (cardiac death, myocardial infarction, or rehospitalization for unstable or progressive angina).

RESULTS

There were 211 patients (31.6%) with STEMI and 457 (68.4%) with NSTEMI. Patients with STEMI and NSTEMI had similar angiographic and IVUS morphologic characteristics. At 3 years, MACE occurred in 22.1% and 19.6%, respectively (hazard ratio [HR] 1.16 [0.81, 1.68], P = .42). There was a higher overall mortality (HR 2.16 [0.94, 4.99], P = .06) and a significantly higher incidence of probable stent thrombosis (HR 4.34 [1.09, 17.36], P = .02) in the STEMI cohort. There were no significant differences between the 2 groups with respect to events related to culprit or to nonculprit lesions. ST-elevation myocardial infarction presentation was not an independent predictor of 3-year MACE (HR 1.14 [0.77, 1.67], P = .52).

CONCLUSION

Patients with STEMI and NSTEMI did not differ with respect to residual nonculprit lesion angiographic or IVUS characteristics and had similar rates of MACE at 3 years, without late "catch-up" in NSTEMI. However, probable stent thrombosis and mortality were higher in the STEMI cohort.

Effects of atorvastatin pretreatment on infarct size in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

Atorvastatin pretreatment has been reported to reduce myocardial damage in patients undergoing percutaneous coronary intervention (PCI). We sought to investigate the effect of atorvastatin pretreatment on infarct size in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

Patients undergoing primary PCI for ST-segment elevation myocardial infarction within 12 hours after symptom onset were randomized to an atorvastatin group (80 mg before PCI and for 5 days after PCI [n = 89]) or a control group (10 mg daily after PCI [n = 84]). The primary end point was infarct size measured by technetium Tc 99m tetrofosmin single-photon emission computed tomography between days 5 and 14.

RESULTS

Baseline clinical, angiographic, and procedural characteristics were not significantly different between groups except for age and current smoking status. There was no significant difference in infarct size (as a percentage of the left ventricle) between groups (22.2% ± 15.5% in the atorvastatin group vs 21.6% ± 15.4% in the control group, P = .79). The median infarct size was 19.0% (interquartile range 9.0-32.0) in the atorvastatin group and 18.0% (9.3-32.5) in the control group (P = .76). Achievement of myocardial blush grade 2/3 and complete ST-segment resolution at 60 minutes after PCI occurred with similar frequency (72.8% vs 81.9%, P = .33 and 43.2% vs 47.5%, P = .57, respectively).

CONCLUSIONS

Pretreatment with high-dose atorvastatin followed by further treatment for 5 days did not reduce infarct size measured by single-photon emission computed tomography in patients undergoing primary PCI.

Comparison of magnetic resonance imaging findings in non-ST-segment elevation versus ST-segment elevation myocardial infarction patients undergoing early invasive intervention

To define causes and pathological mechanisms underlying differences in clinical outcomes, we compared the findings of contrast-enhanced magnetic resonance imaging (CE-MRI) between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI). In 168 patients undergoing early invasive intervention for STEMI (n = 113) and NSTEMI (n = 55), CE-MRI was performed a median of 6 days after the index event. Infarct size was measured on delayed-enhancement imaging, and area at risk (AAR) was quantified on T2-weighted images. The median infarct size was significantly smaller in the NSTEMI group than in the STEMI group (10.7% [5.6-18.1] vs. 19.2% [10.3-30.7], P < 0.001). Although there was a trend toward a greater myocardial salvage index ([AAR - infarct size] × 100/AAR) in the NSTEMI group compared to the STEMI group (48.2 [30.4-66.8] vs. 40.5 [24.8-53.5], P = 0.056), myocardial salvage index was similar between the groups in patients with anterior infarction (39.6 [20.0-54.9] vs. 35.5 [23.2-53.4], P = 0.96). The NSTEMI group also had a significantly lower extent of microvascular obstruction and a smaller number of segments with >75% of infarct transmurality relative to the STEMI group (0% [0-0.6] vs. 0.9% [0-2.3], P < 0.001 and 3.0 ± 2.3 vs. 4.6 ± 2.9, P = 0.001, respectively). Myocardial hemorrhage was detected less frequently in the NSTEMI group than the STEMI group (22.6% vs. 43.8%, P = 0.029). In the multivariate analysis, baseline Thrombolysis In Myocardial Infarction flow grade 3 and hemorrhagic infarction were closely associated with ST-segment elevation (OR 0.32, 95% CI 0.13-0.81, P = 0.017; OR 5.66, 95% CI 1.77-18.12, P = 0.003, respectively). In conclusion, in vivo pathophysiological differences revealed by CE-MRI assessment include more favorable infarct size, AAR, myocardial salvage and reperfusion injury in patients with NSTEMI compared to those with STEMI undergoing early invasive intervention.