2009 Focused Updates: ACC/AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction (updating the 2004 Guideline and 2007 Focused Update) and ACC/AHA/SCAI Guidelines on Percutaneous Coronary Intervention (updating the 2005 Guideline and 2007 Focused Update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines

Six-month versus 12-month dual antiplatelet therapy after implantation of drug-eluting stents: the Efficacy of Xience/Promus Versus Cypher to Reduce Late Loss After Stenting (EXCELLENT) randomized, multicenter study

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) after implantation of drug-eluting coronary stents remains undetermined. We aimed to test whether 6-month DAPT would be noninferior to 12-month DAPT after implantation of drug-eluting stents.

METHODS AND RESULTS

We randomly assigned 1443 patients undergoing implantation of drug-eluting stents to receive 6- or 12-month DAPT (in a 1:1 ratio). The primary end point was a target vessel failure, defined as the composite of cardiac death, myocardial infarction, or ischemia-driven target vessel revascularization at 12 months. Rates of target vessel failure at 12 months were 4.8% in the 6-month DAPT group and 4.3% in the 12-month DAPT group (the upper limit of 1-sided 95% confidence interval, 2.4%; P=0.001 for noninferiority with a predefined noninferiority margin of 4.0%). Although stent thrombosis tended to occur more frequently in the 6-month DAPT group than in the 12-month group (0.9% versus 0.1%; hazard ratio, 6.02; 95% confidence interval, 0.72-49.96; P=0.10), the risk of death or myocardial infarction did not differ in the 2 groups (2.4% versus 1.9%; hazard ratio, 1.21; 95% confidence interval, 0.60-2.47; P=0.58). In the prespecified subgroup analysis, target vessel failure occurred more frequently in the 6-month DAPT group than in the 12-month group (hazard ratio, 3.16; 95% confidence interval, 1.42-7.03; P=0.005) among diabetic patients.

CONCLUSIONS

Six-month DAPT did not increase the risk of target vessel failure at 12 months after implantation of drug-eluting stents compared with 12-month DAPT. However, the noninferiority margin was wide, and the study was underpowered for death or myocardial infarction. Our results need to be confirmed in larger trials.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00698607.

Comparison of direct stenting with conventional stent implantation in acute myocardial infarction

Small studies have suggested that direct stenting without balloon predilatation in ST-segment elevation myocardial infarction may reduce microcirculatory dysfunction. To examine the clinical benefits of direct stenting in a large cohort of patients who underwent primary percutaneous coronary intervention treated with contemporary pharmacotherapy, the 1-year outcomes from the multicenter, randomized Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial were analyzed. A total of 3,602 patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention were enrolled. The present study cohort consisted of 2,528 patients in whom single lesions (excluding bypass grafts) were treated with stent implantation. At operator discretion, direct stenting was attempted in 698 patients (27.6%), and stenting was performed after predilatation in 1,830 patients (72.4%). Propensity-score matching was performed to reduce bias. Direct stenting was successful in 677 patients (97.0%). ST-segment resolution at 60 minutes after the procedure was improved in patients who underwent direct compared to conventional stenting (median 74.8% vs 68.9%, respectively, p = 0.01). At 1-year follow-up, direct compared to conventional stenting was associated with a significantly lower rate of all-cause death (1.6% vs 3.8%, p = 0.01) and stroke (0.3% vs 1.1%, p = 0.049), with nonsignificant differences in target lesion revascularization, myocardial infarction, stent thrombosis, and major bleeding. Death at 1 year remained significantly lower in the direct stenting group after multivariate adjustment (hazard ratio 0.42, 95% confidence interval 0.21 to 0.86, p = 0.02) and in a propensity score-based analysis (hazard ratio 0.92, 95% confidence interval 0.88 to 0.95, p = 0.02). In conclusion, compared to stent implantation after predilatation, direct stenting is safe and effective in appropriately selected lesions in patients with ST-segment elevation myocardial infarction who undergo primary percutaneous coronary intervention and may result in improved survival.

[Kounis syndrome]

Kounis syndrome was described in 1991 by Kounis and Zavras as the coincidental occurrence of acute coronary syndromes with allergic reactions (anaphylactic or anaphylactoid). Today, allergic angina and allergic myocardial infarction are referred to as Kounis syndrome, and the latter has been reported in association with a variety of drugs, insect stings, food, environmental exposures and medical conditions, among other factors. The incidence is not known, as most of the available information comes from case reports or small case series. In this article, the clinical aspects, diagnosis, pathogenesis, related conditions and therapeutic management of the syndrome are discussed.

The role of cardiovascular magnetic resonance in patients with acute coronary syndromes

Cardiovascular magnetic resonance (CMR) imaging is a recognized technique for characterization of myocardial tissue in stable ischemic heart disease. In addition, CMR is emerging as a noninvasive imaging tool that can provide supporting information to guide treatment in acute coronary syndromes (ACSs). The advantages of using CMR acutely could potentially include triage/differential diagnosis in patients presenting with chest pain and troponin rise but without diagnostic electrocardiogram changes, assessment of severity of myocardial injury (irreversible vs reversible damage) in patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction, and risk stratification and assessment of prognosis in patients with ACS. This review evaluates a potential clinical role of CMR in the acute setting, highlighting its advantages and limitations. This critical approach emphasizes areas of uncertainty and ongoing controversies but aims to equip the reader to evaluate the potential clinical application and the practicalities of CMR in patients presenting with ACS.

Treatment of patients with left main coronary artery disease

OPINION STATEMENT

Considering lesion priority and its clinical consequences, coronary artery bypass grafting (CABG) has been a treatment of choice for revascularization in patients with significant left main coronary artery (LMCA) disease, However, with remarkable advancements in techniques of percutaneous coronary intervention (PCI), supporting devices, and adjunctive pharmacologic therapy, PCI with stenting has emerged to be a less invasive and feasible revascularization treatment for these patients. The cumulative evidence suggests that the safety outcomes such as mortality or composite of death, myocardial infarction, and stroke are similar among PCI and CABG, with the only difference being the rate of repeat revascularization. Based on these data, the current guideline of revascularization of LMCA disease has adopted an increasing off-label experience with stenting and clinical studies and been updated to partly approve PCI as a viable alternative (in level of class IIb) in selected patients. The choice of PCI or CABG for unprotected LMCA disease depends on several clinical and anatomic features, ensuring crucial patient selection to be a cornerstone for achieving favorable long-term outcomes. In patients with very complex anatomic features and concomitant diffuse multivessel disease, CABG is preferred so as to avoid procedural and future thrombotic risks and to provide more complete revascularization. By contrast, in patients with relatively simple LMCA disease, such as ostial/shaft LMCA disease, isolated LMCA disease (with or without one or two-vessel involvement), and LMCA disease with low SYNTAX score, PCI is an alternative, and in some cases a preferred, strategy to reduce surgical risks (eg, stroke and in-hospital events following major surgery). For the future, ongoing large clinical trials might also boost interventional cardiologists to select PCI with stenting as an alternative revascularization strategy for unprotected LMCA disease. This evidence will most likely change the current clinical practice and guidelines of optimal revascularization strategy for unprotected LMCA disease.

Recording of quality indicators in the management of acute coronary syndromes: predictors of reperfusion times

BACKGROUND

There is wide variation in recording of reperfusion times in the management of ST segment elevation acute coronary syndromes (ACS). We investigated factors that could predict time to reperfusion.

METHODS

Single-centre, retrospective study of all consecutive patients admitted for primary PCI from June 2009 to October 2010. Door-to-artery (D2A) and Door-to-balloon (D2B) times were calculated from times noted by cathlab. nurses and compared with times from digital recordings of PCI procedures. Predictors of time to reperfusion were identified by logistic regression.

RESULTS

300 patients were included. Median (interquartile range) D2B time recorded by cathlab. nurses (D2B-CN) was 35.5 (24; 52) minutes, 32 (20; 51) min from PCI recordings (D2B-PCI). Average difference between D2B-CN and D2B-PCI was 6.2 min (P < 0.0001). Concordance of percent patients with a D2B time < 90 and < 45 min was mediocre, kappa coefficients 0.44 (95% CI: 0.10-0.79) and 0.68 (95% CI: 0.57-0.80) respectively. By multivariate analysis, older patients had longest D2A times (P = 0.04); patients with longest D2A and D2B times more frequently had elevated creatinine (P = 0.002 (D2A), P = 0.0003 (D2B). Organizational aspects did not influence reperfusion times.

CONCLUSION

Data regarding reperfusion times are unreliable when recorded by nurses. Age and creatinine levels are significantly associated with reperfusion times, whereas organizational aspects are not.

Long-term effects of percutaneous coronary intervention of the totally occluded infarct-related artery in the subacute phase after myocardial infarction

BACKGROUND

Despite observations suggesting a benefit for late opening of totally occluded infarct-related arteries after myocardial infarction, the Occluded Artery Trial (OAT) demonstrated no reduction in the composite of death, reinfarction, and class IV heart failure over a 2.9-year mean follow-up. Follow-up was extended to determine whether late trends would favor either treatment group.

METHODS AND RESULTS

OAT randomized 2201 stable patients with infarct-related artery total occlusion >24 hours (calendar days 3-28) after myocardial infarction. Patients with severe inducible ischemia, rest angina, class III-IV heart failure, and 3-vessel/left main disease were excluded. We conducted extended follow-up of enrolled patients for an additional 3 years for the primary end point and angina (6-year median survivor follow-up; longest, 9 years; 12 234 patient-years). Rates of the primary end point (hazard ratio, 1.06; 95% confidence interval, 0.88-1.28), fatal and nonfatal myocardial infarction (hazard ratio, 1.25; 95% confidence interval, 0.89-1.75), death, and class IV heart failure were similar for the percutaneous coronary intervention (PCI) and medical therapy alone groups. No interactions between baseline characteristics and treatment group on outcomes were observed. The vast majority of patients at each follow-up visit did not report angina. There was less angina in the PCI group through early in follow-up; by 3 years, the between group difference was consistently <4 patients per 100 treated and not significantly different, although there was a trend toward less angina in the PCI group at 3 and 5 years. The 7-year rate of PCI of the infarct-related artery during follow-up was 11.1% for the PCI group compared with 14.7% for the medical therapy alone group (hazard ratio, 0.79; 95% confidence interval, 0.61-1.01; P=0.06).

CONCLUSIONS

Extended follow-up of the OAT cohort provides robust evidence for no reduction of long-term rates of clinical events after routine PCI in stable patients with a totally occluded infarct-related artery and without severe inducible ischemia in the subacute phase after myocardial infarction.

Comparison of bleeding complications and one-year survival of low molecular weight heparin versus unfractioned heparin for acute myocardial infarction in elderly patients. The FAST-MI registry

BACKGROUND

There are limited data on the safety and efficacy of low molecular weight heparin (LMWH) in elderly patients with acute myocardial infarction (AMI).

METHODS

We aimed to compare LMWH with unfractioned heparin (UFH) in the management of AMI in elderly patients. FAST-MI is a nationwide registry carried out over a 1-month period in 2005, including consecutive patients with AMI admitted to intensive care unit <48 h from symptom onset in 223 participating centers. We assessed the impact of LMWH on bleeding, the need for blood transfusion and one-year survival in elderly patients (≥ 75 years).

RESULTS

963 patients treated with heparin were included (mean age 82 ± 5 years; 51% women; 42.5% ST-elevation myocardial infarction). Major bleeding (2.4% vs. 6.1%, P=0.004) and blood transfusions (4.6% vs. 9.7%, P=0.002) were significantly less frequent with LMWH compared with the UFH, a difference that persisted after multivariate adjustment (OR=0.41, 95% CI: 0.20-0.83 and OR=0.49, 95% CI: 0.28-0.85, respectively). One-year survival and stroke and reinfarction-free survival were also significantly higher with LMWH compared with UFH (OR=0.66, 95% CI: 0.50-0.85 and OR=0.71, 95% CI: 0.56-0.91, respectively). In two cohorts of patients matched on a propensity score for getting LMWH and with similar baseline characteristics (328 patients per group), major bleeding and transfusion were significantly lower while one-year survival was significantly higher in patients receiving LMWH.

CONCLUSIONS

The present data show that in elderly patients admitted for AMI, use of LMWH is associated with less bleeding, less need for transfusion, and higher survival, compared with the use of UFH.

Arterial thrombosis--insidious, unpredictable and deadly

The formation of blood clots--thrombosis--at sites of atherosclerotic plaque rupture is a major clinical problem despite ongoing improvements in antithrombotic therapy. Progress in identifying the pathogenic mechanisms regulating arterial thrombosis has led to the development of newer therapeutics, and there is general anticipation that these treatments will have greater efficacy and improved safety. However, major advances in this field require the identification of specific risk factors for arterial thrombosis in affected individuals and a rethink of the 'one size fits all' approach to antithrombotic therapy.

Benefit of transferring ST-segment-elevation myocardial infarction patients for percutaneous coronary intervention compared with administration of onsite fibrinolytic declines as delays increase

BACKGROUND

Although randomized trials suggest that transfer for primary percutaneous coronary intervention (X-PCI) in ST-segment-elevation myocardial infarction is superior to onsite fibrinolytic therapy (O-FT), the generalizability of these findings to routine clinical practice is unclear because door-to-balloon (XDB) times are rapid in randomized trials but are frequently prolonged in practice. We hypothesized that delays resulting from transfer would reduce the survival advantage of X-PCI compared with O-FT.

METHODS AND RESULTS

ST-segment-elevation myocardial infarction patients enrolled in the National Registry of Myocardial Infarction (NRMI) within 12 hours of pain onset were identified. Propensity matching of patients treated with X-PCI and O-FT was performed, and the effect of PCI-related delay on in-hospital mortality was assessed. PCI-related delay was calculated by subtracting the XDB from the door-to-needle time in each matched pair. Conditional logistic regression adjusted for patient and hospital variables identified the XDB door-to-needle time at which no mortality advantage for X-PCI over O-FT was present. Eighty-one percent of X-PCI patients were matched (n=9506) to O-FT patients (n=9506). In the matched cohort, X-PCI was performed with delays >90 minutes in 68%. Multivariable analysis found no mortality advantage for X-PCI over O-FT when XDB door-to-needle time exceeded ≈120 minutes.

CONCLUSION

PCI-related delays are extensive among patients transferred for X-PCI and are associated with poorer outcomes. No differential excess in mortality was seen with X-PCI compared with O-FT even with long PCI-related delays, but as XDB door-to-needle time times increase, the mortality advantage for X-PCI over O-FT declines.

Statin use in outpatients with obstructive coronary artery disease

BACKGROUND

Clinical trials have shown that statin therapy reduces cardiovascular morbidity and mortality in patients with coronary artery disease (CAD), even among patients with low-density lipoprotein cholesterol levels <100 mg/dL. We sought to determine the extent to which patients with obstructive CAD in routine outpatient care are treated with statins, nonstatins, or no lipid-lowering therapy.

METHODS AND RESULTS

Within the American College of Cardiology's Practice Innovation and Clinical Excellence (PINNACLE) outpatient registry, we examined rates of treatment with statin and nonstatin medications in 38 775 outpatients with obstructive CAD (history of myocardial infarction or coronary revascularization) and without documented contraindications to statin therapy. Among these patients, 30 160 (77.8%) were prescribed statins, 2042 (5.3%) were treated only with nonstatin lipid-lowering medications, and 6573 (17.0%) were untreated. Lack of medical insurance was associated with no statin treatment, and male sex, coexisting hypertension, and a recent coronary revascularization were associated with statin treatment. Among those not on any lipid-lowering therapy, low-density lipoprotein cholesterol levels were available for 51.2% (3365/6573). Among these untreated patients, low-density lipoprotein cholesterol levels were <100 mg/dL in 1794 patients (53.3%) and ≥ 100 mg/dL in 1571 patients (46.7%).

CONCLUSIONS

Despite robust clinical trial evidence, a substantial number of patients with obstructive CAD remain untreated with statins. A small proportion were treated with nonstatin therapy, and 1 in 6 patients was simply untreated; half of the untreated patients had low-density lipoprotein cholesterol values <100 mg/dL. These findings illustrate important opportunities to improve lipid management in outpatients with obstructive CAD.

Helicopter scene response for a STEMI patient transported directly to the cardiac catheterization laboratory

At 2:10 pm, a 40-year-old Caucasian woman with no known medical history called 911 complaining of substernal, crushing chest pain that had started 2 to 3 hours before she called emergency medical services (EMS). EMS arrived at 2:24 pm and obtained a 12-lead electrocardiogram (ECG) diagnostic of ST-segment elevation myocardial infarction (STEMI) at 2:36 pm. University Air Care was requested by local EMS at 2:42 pm to respond directly to the cardiac scene in rural Ohio for rapid transport to a facility capable of performing percutaneous coronary intervention (PCI). The closest PCI-capable facility was approximately 35 minutes away by ground or 13 minutes by air. The closest non-PCI hospital was approximately 20 minutes away by ground (Fig. 1).

Triple therapy in hospitalized patients: facts and controversies

The use of triple therapy (warfarin plus dual antiplatelet therapy) has increased in recent years due to an aging population with a higher risk for atrial fibrillation, as well as the increased use of coronary stents for acute coronary syndromes. Triple therapy confers a higher bleeding risk than either warfarin or dual antiplatelet therapy alone. However, warfarin alone is inadequate for patients with indications for triple therapy because of an unacceptable risk of stent thrombosis, and dual antiplatelet therapy is inferior to warfarin for the prevention of ischemic strokes in patients with atrial fibrillation, mechanical valves, or intraventricular thrombosis. Hospitalists face the challenge of balancing the aforementioned risks; the optimal management of these patients requires knowledge of the relevant literature and expertise. In this paper, we review the current literature on antiplatelet and anticoagulant combinations in patients with atrial fibrillation and coronary stents in order to improve adherence to published guidelines and to reduce the risk of bleeding.

Effect of CYP2C19*2 and *3 loss-of-function alleles on platelet reactivity and adverse clinical events in East Asian acute myocardial infarction survivors treated with clopidogrel and aspirin

BACKGROUND

As compared with whites, East Asians more often carry the cytochrome P450 (CYP) 2C19 loss-of-function (LOF) allele with the CYP2C19*3 variant. The influence of the CYP2C19 LOF alleles (*2 and *3) on clopidogrel response and clinical outcomes in East Asians with acute myocardial infarction (AMI) has not been reported. We sought to evaluate the effect of the CYP2C19 variants on clopidogrel pharmacodynamics and long-term prognosis in these patients.

METHODS AND RESULTS

Patients who survived an AMI (n=266) were enrolled in a single-center registry. Predischarge platelet reactivity was assessed with light transmittance aggregometry and the VerifyNow P2Y12 assay; the CYP2C19*2, *3, *17 and ABCB1 3435C>T variants were determined. The primary clinical end point was the composite of cardiovascular death, nonfatal MI, and ischemic stroke. The median exposure to clopidogrel was 21 months (interquartile range, 13-29). The ABCB1 3435C>T was not related to clopidogrel response or cardiovascular events. Carriage of the CYP2C19 LOF variant allele was relatively high (60.9%, n=162; *2/*17=2, *3/*17=1, *1/*2=96, *1/*3=29, *2/*2=20, and *2/*3=14). Platelet reactivity increased proportionally according to the number of the CYP2C19 LOF alleles. In a multivariate regression analysis, the risk of high on-treatment platelet reactivity (HPR) increased depending on the number of CYP2C19 LOF allele [1 LOF allele; odds ratio (OR), 1.8; 95% confidence interval (CI), 0.8 to 4.2, P=0.152; and 2 LOF alleles; OR, 2.8; 95% CI, 1.2 to 6.5; P=0.016]; platelet reactivity and the rate of HPR did not differ between the CYP2C19*2 versus *3 allele carriage. In addition, cardiovascular event occurrence increased according to the number of the CYP2C19 LOF allele; compared with noncarriers, carriers of 1 [hazard ratio (HR), 3.1; 95% CI, 0.8 to 11.6; P=0.089] and 2 CYP2C19 LOF allele(s) (HR, 10.1; 95% CI, 1.8-58.8; P=0.008) were associated with clinical end point. The clinical impact of the CYP2C19*2 versus *3 allele carriage also did not differ.

CONCLUSIONS

Among East Asian patients who survived an AMI, the CYP2C19 LOF allele carriage appears to affect clopidogrel pharmacodynamics and cardiovascular events according to the number of the CYP2C19 LOF allele; the influence of the CYP2C19*2 and *3 alleles on clopidogrel response and long-term outcomes does not differ.

Mode of death after contemporary percutaneous coronary intervention: a report from the Evaluation of Drug Eluting Stents and Ischemic Events registry

BACKGROUND

When selecting clinical trial end points, some investigators prefer cardiovascular death (CVD) while others believe that all-cause mortality is more relevant. However, the relative contribution of CVD to 1-year mortality after contemporary percutaneous coronary intervention (PCI) is not known.

METHODS

We evaluated the mode of death (MOD) in EVENT, a prospective PCI registry at 55 US hospitals. Vital status was assessed at 6 and 12 months as part of the study protocol, and MOD was independently reviewed in blinded fashion.

RESULTS

Between 2004 and 2007, EVENT enrolled 10,144 patients of whom 295 (2.9%) died within the first year: 51 (17%) ≤30 days; and 244 (83%) between 31 and 365 days after index PCI. Overall, CVD accounted for 42% of deaths, and no clear cause could be identified in a substantial subgroup (25% of deaths). Among patients who died ≤30 days, the MOD was more likely to be CVD (odds ratio 3.96, 95% CI 2.08-7.55), whereas the incidence of CVD and non-CVD was similar after 30 days. Findings were similar after a series of sensitivity analyses including reassignment of unknown MOD to the CVD category, using multiple imputation modeling, or when evaluating MOD in prespecified subgroups of patients with diabetes, acute coronary syndromes, or left ventricular dysfunction.

CONCLUSIONS

Among unselected PCI patients, 1-year mortality is approximately 3%, and CVD is confirmed in <50% of all deaths. Regardless of analytic approach, CVD is the primary contributor to overall mortality during the first 30 days after PCI, whereas rates of CVD and non-CVD are remarkably similar after the first month after PCI.

The challenge of triaging chest pain patients: the bernese university hospital experience

Accurate diagnosis of the causes of chest pain and dyspnea remain challenging. In this preliminary observational study with a 5-year follow-up, we attempted to find a simplified approach to selecting patients with chest pain needing immediate care based on the initial evaluation in ED. During a 24-month period were randomly selected 301 patients and a conditional inference tree (CIT) was used as the basis of the prognostic rule. Common diagnoses were musculoskeletal chest pain (27%), ACS (19%) and panic attack (12%). Using variables of ACS symptoms we estimated the likelihood of ACS based on a CIT to be high at 91% (32), low at 4% (198) and intermediate at 20.5–40% in (71) patients. Coronary catheterization was performed within 24 hours in 91% of the patients with ACS. A culprit lesion was found in 79%. Follow-up (median 4.2 years) information was available for 70% of the patients. Of the 164 patients without ACS who were followed up, 5 were treated with revascularization for stable angina pectoris, 2 were treated with revascularization for myocardial infarction, and 25 died. Although a simple triage decision tree could theoretically help to efficient select patients needing immediate care we need also to be vigilant for those presenting with atypical symptoms.

Long-term prognosis of first myocardial infarction according to the electrocardiographic pattern (ST elevation myocardial infarction, non-ST elevation myocardial infarction and non-classified myocardial infarction) and revascularization procedures

The aim of this study was to describe differences in the characteristics and short- and long-term prognoses of patients with first acute myocardial infarction (MI) according to the presence of ST-segment elevation or non-ST-segment elevation. From 2001 and 2003, 2,048 patients with first MI were consecutively admitted to 6 participating Spanish hospitals and categorized as having ST-segment elevation MI (STEMI), non-ST-segment elevation MI (NSTEMI), or unclassified MI (pacemaker or left bundle branch block) according to electrocardiographic results at admission. The proportions of female gender, hypercholesterolemia, hypertension, and diabetes were higher among NSTEMI patients than in the STEMI group. NSTEMI 28-day case fatality was lower (2.99% vs 5.26%, p = 0.02). On multivariate analysis, the odds ratio of 28-day case fatality was 2.23 for STEMI patients compared to NSTEMI patients (95% confidence interval 1.29 to 3.83, p = 0.004). The multivariate adjusted 7-year mortality for 28-day survivors was higher in NSTEMI than in STEMI patients (hazard ratio 1.31, 95% confidence interval 1.02 to 1.68, p = 0.035). However, patients with unclassified MI presented the highest short- and long-term mortality (11.8% and 35.4%, respectively). The excess of short-term mortality in unclassified and STEMI patients was mainly observed in those patients not treated with revascularization procedures. In conclusion, patients with first NSTEMI were older and showed a higher proportion of previous coronary risk factors than STEMI patients. NSTEMI patients had lower 28-day case fatality but a worse 7-year mortality rate than STEMI patients. Unclassified MI presented the worst short- and long-term prognosis. These results support the invasive management of patients with acute coronary syndromes to reduce short-term case fatality.

Clinical efficacy and safety of intracoronary vs. intravenous abciximab administration in STEMI patients undergoing primary percutaneous coronary intervention: a meta-analysis of randomized trials

Adjunctive therapy with abciximab has been proven to reduce mortality and reinfarction in patients with ST-elevation myocardial infarction (STEMI) referred to invasive management. Standard abciximab regimen consists of an intravenous (IV) bolus followed by a 12-h IV infusion. Experimental studies and small clinical trials suggest the superiority of intracoronary (IC) injection of abciximab over the IV route. We aimed to perform a meta-analysis of randomized controlled trials to assess the clinical efficacy and safety of IC vs. IV abciximab administration in STEMI patients undergoing primary percutaneous coronary intervention (PPCI). The primary endpoint was mortality, while recurrent myocardial infarction and target vessel revascularization (TVR) were selected as secondary endpoints. The safety endpoint was the risk of major bleeding complications. A total of six randomized trials were finally included in the meta-analysis, enrolling a total of 1246 patients. Compared to IV route, IC abciximab was associated with a significant reduction in mortality (odds ratio, OR [95% confidence interval (CI)] =0.43 [0.20-0.94], p=0.03), and TVR (OR [95% CI] =0.53 [0.29-0.99], p=0.05). No differences in terms of recurrent myocardial infarction (OR [95% CI] =0.54 [0.23-1.28], p=0.17) or major bleeding complications (OR [95% CI] =0.91 [0.46-1.79], p=0.79) were observed between the two strategies. The present meta-analysis showed that IC administration of abciximab is associated with significant benefits in mortality at short-term follow-up compared to IV abciximab administration, without any excess of major bleeding in STEMI patients undergoing PPCI. However, further trials are warranted to establish the optimal strategy of abciximab treatment in this setting.

Duration of dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent implantation: a review of the current guidelines and literature

Dual antiplatelet therapy is the mainstay of medical treatment after percutaneous coronary intervention regarding the risk of stent thrombosis occurrence. Since the beginning of the stenting era, antiplatelet regimens have evolved according to the emerging and widespread diffusion of new devices and more challenging indications for their use. In the past years, concerns have been raised about the safety of drug-eluting stent implantation with regard to late and very late stent thrombosis. Thus, the length of dual antiplatelet therapy has been progressively increased with marked individual and local differences. However, prolonged antiplatelet therapy leads to increased risk of bleeding, especially in the setting of surgical procedures, traumas, and/or other diseases. To date, the exact duration of dual antiplatelet therapy after drug-eluting stent implantation is still debated in the literature. The aim of this article is to review the literature and the current guidelines on the risks and benefits of pursuing dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent implantation.

Revascularization for unprotected left main coronary artery disease: an evolution in clinical decision making

Coronary artery bypass grafting (CABG) has been considered the standard therapy for unprotected (nonrevascularized) left main coronary disease (ULM). However, increasing experience with ULM percutaneous coronary intervention (PCI) has resulted in high procedural success and favorable early and late clinical outcomes. In particular, reduction in clinical restenosis with drug-eluting stents, evolution of procedural technique, and demonstration of favorable outcomes from comparative trials with CABG have promoted consideration of PCI as an alternative revascularization strategy in selected patients with ULM disease. This review summarizes the results from comparative studies examining PCI versus CABG for ULM disease, discusses changing indications for ULM PCI and identifies outstanding issues that must be considered before further advancing treatment recommendations.

Study design and rationale for the Stabilization of pLaques usIng Darapladib-Thrombolysis in Myocardial Infarction (SOLID-TIMI 52) trial in patients after an acute coronary syndrome

BACKGROUND

Higher levels of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) are associated with a higher risk of cardiovascular events and may play a causal role in atherogenesis. Darapladib inhibits Lp-PLA(2) activity in plasma and in arterial plaques and may confer clinical benefit in preventing cardiovascular events.

STUDY DESIGN

The SOLID-TIMI 52 trial is a randomized, double-blind, placebo-controlled, multicenter, event-driven trial. Approximately 13,000 subjects are being randomized to darapladib (160 mg enteric-coated tablet daily) or matching placebo within 30 days of hospitalization with an acute coronary syndrome. The primary end point is the composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. Secondary end points include major and total coronary events, individual components of the primary end point, and all-cause mortality. The study will continue until approximately 1,500 primary end point events have occurred to achieve 90% power to detect a 15.5% reduction in the primary end point. The median treatment duration is anticipated to be approximately 3 years, with a total study duration of approximately 4.1 years.

CONCLUSIONS

The SOLID-TIMI 52 trial will determine the clinical benefit of direct inhibition of Lp-PLA(2) activity with darapladib in patients after an acute coronary syndrome.

Thin-cap fibroatheroma as high-risk plaque for microvascular obstruction in patients with acute coronary syndrome

BACKGROUND

Plaque contents can cause microvascular impairment, which is an important determinant of clinical outcomes in patients with acute coronary syndrome (ACS). We hypothesized that percutaneous coronary intervention (PCI) for thin-cap fibroatheroma (TCFA) could easily disrupt the fibrous cap and expose the contents of plaque to coronary flow, possibly resulting in microvascular obstruction (MVO). The purpose of this study was to investigate whether TCFA was associated with MVO after PCI in patients with ACS.

METHODS AND RESULTS

We enrolled 115 patients with ACS who were successfully recanalized with PCI. The patients were divided into a ruptured plaque group (n=59), a nonrupture with TCFA group (n=21), and a nonrupture and non-TCFA group (n=35), according to optical coherence tomography findings of the culprit lesion. Using contrast-enhanced MRI, we assessed MVO. There were no statistically significant differences in patient characteristics. The nonrupture with TCFA group more frequently presented MVO (ruptured plaque, 27%; versus nonrupture with TCFA, 43%; versus non-TCFA and nonrupture, 9%; P=0.012). The prevalence of MVO increases as cap thickness decreases.

CONCLUSIONS

TCFA is more frequently associated with MVO after PCI. TCFA is a high-risk plaque for MVO after PCI in patients with ACS.

Shock index: a simple clinical parameter for quick mortality risk assessment in acute myocardial infarction

BACKGROUND

Primary percutaneous coronary intervention (PCI) has become the preferred reperfusion strategy in patients with ST-segment elevation myocardial infarction and cardiogenic shock. Early identification of patients at risk for developing cardiogenic shock allows rapid decision making to determine reperfusion and transportation to a PCI centre. The aim of this analysis was to evaluate shock index (SI) as a marker for patients at risk of cardiogenic shock.

METHODS

A total of 644 consecutive patients (73% male) with acute myocardial infarction with ST elevations were analyzed retrospectively. Primary PCI was performed in 92% of patients, and 7% of patients underwent rescue PCI. The SI parameter was defined as the ratio of heart rate to systolic blood pressure at hospital admission.

RESULTS

SI (odds ratio [OR], 81.26; 95% confidence interval [CI], 9.76-676.51; P<0.001), age (OR, 1.17; 95% CI, 1.08-1.26; P<0.001), and diabetes (OR, 4.94; 95% CI, 1.44-16.97; P<0.011) were independent predictors of mortality. In the group of patients with SI≥0.8, 20% died, whereas in the group with SI<0.8, 4% of patients died (P<0.01).

CONCLUSIONS

The proposed clinical parameter SI correlates with patients' prognosis and could therefore be used as a simple indicator of mortality risk of acute myocardial infarction. The simplicity of this proposed index makes its use accessible in large-scale clinical practices for risk stratification during first contact with patients.

Beneficial effects of intracoronary tirofiban bolus administration following upstream intravenous treatment in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: the ICT-AMI study

BACKGROUND

We investigated whether an additional intracoronary tirofiban bolus administration following upstream intravenous treatment could further improve myocardial reperfusion and clinical outcome in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

METHODS

A total of 453 eligible STEMI patients were randomly allocated to intracoronary bolus administration of tirofiban (10 μg/kg; n=229) or saline (10 mL; n=224) during primary PCI, followed by intravenous tirofiban infusion (0.15 μg/kg/min) for 24-36 h. Serum levels of P-selectin, vWF, CD40L and serum amyloid A (SAA) in the coronary sinus were measured before and after intracoronary bolus administration. The primary endpoint was ST-segment resolution (STR) at 90 min after the procedure. Second endpoints included corrected TIMI frame count (cTFC), left ventricular volumes and ejection fraction (EF), and major adverse cardiac events (MACE) at 30-day and 6-month follow-up.

RESULTS

Intracoronary tirofiban administration resulted in a higher rate of completed STR (59.0% vs. 44.6%, P=0.002), lower cTFC (21.6±5.4 vs. 23.7±7.8, P=0.048), and significantly reduced coronary sinus levels of P-selectin, vWF, CD40L and SAA. Patients treated with intracoronary tirofiban had a trend toward less MACE at 30 days (3.1% vs. 6.7%, P=0.072). At 6 months, left ventricular end-systolic volume was smaller, EF was higher and MACE-free survival was improved (96.1% vs. 90.6%, P=0.020) in the intracoronary tirofiban group.

CONCLUSIONS

An additional intracoronary tirofiban bolus administration following upstream intravenous treatment reduces coronary circulatory platelet activation and inflammatory process, and significantly improves myocardial reperfusion and left ventricular function as well as 6-month MACE-free survival for STEMI patients undergoing primary PCI.

Cardiac myosin binding protein-C is a potential diagnostic biomarker for myocardial infarction

Cardiac myosin binding protein-C (cMyBP-C) is a thick filament assembly protein that stabilizes sarcomeric structure and regulates cardiac function; however, the profile of cMyBP-C degradation after myocardial infarction (MI) is unknown. We hypothesized that cMyBP-C is sensitive to proteolysis and is specifically increased in the bloodstream post-MI in rats and humans. Under these circumstances, elevated levels of degraded cMyBP-C could be used as a diagnostic tool to confirm MI. To test this hypothesis, we first established that cMyBP-C dephosphorylation is directly associated with increased degradation of this myofilament protein, leading to its release in vitro. Using neonatal rat ventricular cardiomyocytes in vitro, we were able to correlate the induction of hypoxic stress with increased cMyBP-C dephosphorylation, degradation, and the specific release of N'-fragments. Next, to define the proteolytic pattern of cMyBP-C post-MI, the left anterior descending coronary artery was ligated in adult male rats. Degradation of cMyBP-C was confirmed by a reduction in total cMyBP-C and the presence of degradation products in the infarct tissue. Phosphorylation levels of cMyBP-C were greatly reduced in ischemic areas of the MI heart compared to non-ischemic regions and sham control hearts. Post-MI plasma samples from these rats, as well as humans, were assayed for cMyBP-C and its fragments by sandwich ELISA and immunoprecipitation analyses. Results showed significantly elevated levels of cMyBP-C in the plasma of all post-MI samples. Overall, this study suggests that cMyBP-C is an easily releasable myofilament protein that is dephosphorylated, degraded and released into the circulation post-MI. The presence of elevated levels of cMyBP-C in the blood provides a promising novel biomarker able to accurately rule in MI, thus aiding in the further assessment of ischemic heart disease.

System delay and timing of intervention in acute myocardial infarction (from the Danish Acute Myocardial Infarction-2 [DANAMI-2] trial)

The interval from the first alert of the healthcare system to the initiation of reperfusion therapy (system delay) is associated with mortality in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention (pPCI). The importance of system delay in patients treated with fibrinolysis versus pPCI has not been assessed. We obtained data on system delay from the Danish Acute Myocardial Infarction-2 study, which randomized 1,572 patients to fibrinolysis or pPCI. The study end points were 30-day and 8-year mortality. The short system delays were associated with reduced absolute mortality in both the fibrinolysis group (<1 hour, 5.6%; 1 to 2 hours, 6.9%; 2 to 3 hours, 9.5%; and >3 hours, 11.5%; test for trend, p = 0.08) and pPCI group (<1 hour, not assessed; 1 to 2 hours, 2.6%; 2 to 3 hours, 7.5%; >3 hours, 7.7%; test for trend, p = 0.02). The lowest 30-day mortality was obtained with pPCI and a system delay of 1 to 2 hours (vs fibrinolysis within <1 hour, adjusted hazard ratio 0.33; 95% confidence interval 0.10 to 1.10; p = 0.07; vs fibrinolysis within 1 to 2 hours, adjusted hazard ratio 0.37; 95% confidence interval 0.14 to 0.95; p = 0.04). pPCI and system delay >3 hours was associated with a similar 30-day and 8-year mortality as fibrinolysis within 1 to 2 hours. In conclusion, short system delays are associated with reduced mortality in patients with ST-segment elevation myocardial infarction treated with fibrinolysis as well as pPCI. pPCI performed with a system delay of <2 hours is associated with lower mortality than fibrinolysis performed with a faster or similar system delay.

Comparison of efficacy and safety of a standard versus a loading dose of clopidogrel for acute myocardial infarction in patients ≥ 75 years of age (from the FAST-MI registry)

Data are lacking on the efficacy and safety of a loading dose (LD) of clopidogrel in elderly patients with acute myocardial infarction (AMI). FAST-MI is a nationwide registry that was carried out over a 1-month period in 2005 and included consecutive patients with AMI admitted to intensive care units <48 hours from symptom onset in 223 participating centers. We assessed the impact of a clopidogrel LD (≥300 mg) compared to a conventional dose (<300 mg) on bleeding, need for blood transfusion, and 30-day and 12-month survivals in 791 elderly patients (≥75 years old, mean age 81 ± 4 years, 48% women, 35% with ST-segment elevation MI) included in this registry. Fifty-nine percent (466 patients) received a clopidogrel LD. Follow-up was >99% complete. Major bleeding and blood transfusions were not significantly different in patients who received a clopidogrel LD (3.2% vs 3.7%, p = 0.72; 5.4% vs 6.2%, p = 0.64, respectively). Early mortality was also not significantly different (10.1 vs 10.8, p = 0.76). Using multivariate analyses, clopidogrel LD did not significantly affect major bleeding or transfusion (odds ratio 1.03, 95% confidence interval 0.49 to 2.17, p = 0.94) and 12-month mortality (hazard ratio 1.00, 95% confidence interval 0.72 to 1.40, p = 0.98). In conclusion, the present data showed that in elderly patients admitted for AMI, use of a LD of clopidogrel compared to a conventional dose was not associated with increased in-hospital bleeding, need for transfusion, or mortality. Large-scale randomized trials are still needed to identify the optimal LD of clopidogrel for elderly patients admitted for AMI.

Effect of paraoxonase-1 polymorphism on clinical outcomes in patients treated with clopidogrel after an acute myocardial infarction

Paraoxonase-1 (PON1) Q192R polymorphism was recently suggested to determine per se clopidogrel response on major cardiovascular events (MACEs). We assessed the impact of PON1, CYP2C19, and ABCB1 polymorphisms on MACE in clopidogrel-treated acute myocardial infarction (AMI) patients (N = 2,210), including those undergoing percutaneous coronary intervention (PCI) (n = 1,538). PON1 polymorphism was not associated with increased risk of in-hospital death and MACEs at 1 year (adjusted hazard ratio (HR) 1.03, 95% confidence interval (CI) 0.66-1.61 and adjusted HR 0.77, 95% CI 0.42-1.41 for QQ versus RR in all and PCI patients, respectively). The presence of two CYP2C19 loss-of-function (LOF) alleles was associated with the risk of in-hospital death and MACEs at 1 year in the overall population (adjusted odds ratio (OR) 3.67, 95% CI 1.05-12.80 and adjusted HR 1.96, 95% CI 1.08-3.54) and in PCI patients (adjusted OR 6.87, 95% CI 2.52-18.72 and adjusted HR 3.06, 95% CI 1.47-6.41). Unlike CYP2C19 polymorphism, PON1 (Q192R) polymorphism is not a major pharmacogenetic contributor of clinical response to clopidogrel in AMI patients.