Improving outcome over time of percutaneous coronary interventions in unstable angina

Comparison Between Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers in Patients with Unstable Angina with Preserved Left Ventricular Systolic Function

The present study evaluated the clinical results of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) treatment in patients with unstable angina (UA) with preserved left ventricular systolic function who underwent percutaneous coronary intervention (PCI) due to uncertainty regarding the long-term prognosis using ACEI or ARB. A total of 1627 UA patients with preserved left ventricular systolic function after PCI were enrolled. After propensity score matching, there were no differences in major adverse cardiovascular and cerebrovascular events (MACCEs) (hazard ratio (HR) = .860, 95% confidence interval (CI): .465-1.590, P = .630), all-cause death (HR = .334, 95% CI: .090-1.238, P = .101), nonfatal myocardial infarction (HR = 4.929, 95% CI: .576-42.195, P = .145), stroke (HR = 1.049, 95% CI: .208-5.290, P = .954) and target vessel revascularization (TVR) (HR = 1.276, 95% CI: .537-3.031, P = .581) between the ACEI and ARB groups. In conclusion, prognoses were comparable between ACEI or ARB treatment in UA patients who had preserved left ventricular systolic function after PCI.

Routine invasive strategies versus selective invasive strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

People with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) are managed with a combination of medical therapy, invasive angiography and revascularisation. Specifically, two approaches have evolved: either a 'routine invasive' strategy whereby all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularisation; or a 'selective invasive' (also referred to as 'conservative') strategy in which medical therapy alone is used initially, with a selection of patients for angiography based upon evidence of persistent myocardial ischaemia. Uncertainty exists as to which strategy provides the best outcomes for these patients. This Cochrane review is an update of a Cochrane review originally published in 2006, to provide a robust comparison of these two strategies in the early management of patients with UA/NSTEMI.

OBJECTIVES

To determine the benefits and harms associated with the following.1. A routine invasive versus a conservative or 'selective invasive' strategy for the management of UA/NSTEMI in the stent era.2. A routine invasive strategy with and without glycoprotein IIb/IIIa receptor antagonists versus a conservative strategy for the management of UA/NSTEMI in the stent era.

SEARCH METHODS

We searched the following databases and additional resources up to 25 August 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, MEDLINE and EMBASE, with no language restrictions.

SELECTION CRITERIA

We included prospective randomised controlled trials (RCTs) that compared invasive with conservative or 'selective invasive' strategies in participants with acute UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

Two review authors screened the records and extracted data in duplicate. Using intention-to-treat analysis with random-effects models, we calculated summary estimates of the risk ratio (RR) with 95% confidence intervals (CIs) for the primary endpoints of all-cause death, fatal and non-fatal myocardial infarction (MI), combined all-cause death or non-fatal MI, refractory angina and re-hospitalisation. We performed further analysis of included studies based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. We assessed the heterogeneity of included trials using Pearson χ² (Chi² test) and variance (I² statistic) analysis. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and the GRADE profiler (GRADEPRO) was used to import data from Review Manager 5.3 (Review Manager) to create Summary of findings (SoF) tables.

MAIN RESULTS

Eight RCTs with a total of 8915 participants (4545 invasive strategies, 4370 conservative strategies) were eligible for inclusion. We included three new studies and 1099 additional participants in this review update. In the all-study analysis, evidence did not show appreciable risk reductions in all-cause mortality (RR 0.87, 95% CI 0.64 to 1.18; eight studies, 8915 participants; low quality evidence) and death or non-fatal MI (RR 0.93, 95% CI 0.71 to 1.2; seven studies, 7715 participants; low quality evidence) with invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. There was appreciable risk reduction in MI (RR 0.79, 95% CI 0.63 to 1.00; eight studies, 8915 participants; moderate quality evidence), refractory angina (RR 0.64, 95% CI 0.52 to 0.79; five studies, 8287 participants; moderate quality evidence) and re-hospitalisation (RR 0.77, 95% CI 0.63 to 0.94; six studies, 6921 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies also at six to 12 months follow-up.Evidence also showed increased risks in bleeding (RR 1.73, 95% CI 1.30 to 2.31; six studies, 7584 participants; moderate quality evidence) and procedure-related MI (RR 1.87, 95% CI 1.47 to 2.37; five studies, 6380 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies.The low quality evidence were as a result of serious risk of bias and imprecision in the estimate of effect while moderate quality evidence was only due to serious risk of bias.

AUTHORS' CONCLUSIONS

In the all-study analysis, the evidence failed to show appreciable benefit with routine invasive strategies for unstable angina and non-ST elevation MI compared to conservative strategies in all-cause mortality and death or non-fatal MI at six to 12 months. There was evidence of risk reduction in MI, refractory angina and re-hospitalisation with routine invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. However, routine invasive strategies were associated with a relatively high risk (almost double the risk) of procedure-related MI, and increased risk of bleeding complications. This systematic analysis of published RCTs supports the conclusion that, in patients with UA/NSTEMI, a selectively invasive (conservative) strategy based on clinical risk for recurrent events is the preferred management strategy.

Inhibition of intimal hyperplasia via local delivery of vascular endothelial growth factor cDNA nanoparticles in a rabbit model of restenosis induced by abdominal aorta balloon injury

In-stent restenosis (ISR) is one of the major factors affecting long-term outcomes of percutaneous coronary interventions. Vascular endothelial growth factor (VEGF) has been hypothesized to have a positive role in preventing ISR, however, this remains controversial. The aim of the present study was to assess whether nanoparticles can be used to deliver VEGF to injured arteries and whether this is beneficial in preventing restenosis. New Zealand White rabbits were randomly divided into a control group, an empty nanoparticles group and a VEGF nanoparticles group (n=6 in each group). Polylactic-polyglycolic acid VEGF nanoparticles were prepared using a phacoemulsification method. A rabbit model of restenosis was established following abdominal aorta balloon injury, and VEGF gene nanoparticles, empty nanoparticles or normal saline were delivered locally at the site of injury via a GENIE Catheter™ perfusion balloon. Intimal proliferation determination and immunohistochemistry analysis were performed at day 28 following arterial injury. Compared with the control and empty nanoparticle groups, the neointima area (0.49±0.09, 0.48±0.08 and 0.19±0.11 mm², respectively; P<0.001) and proliferation index (0.32±0.03, 0.32±0.05 and 0.13±0.06, respectively; P<0.001) were significantly lower in the VEGF nanoparticles group. In addition, in the VEGF nanoparticles group, the immunoreactivity of α-actin and proliferating cell nuclear antigen were significantly lower (P≤0.001), while the immunoreactivity of VEGF was higher (P=0.01). Therefore, the results revealed that local delivery of VEGF gene nanoparticles reduced intimal thickening and cell proliferation following abdominal aorta balloon injury in a rabbit model, demonstrating the efficacy of this therapy against restenosis.

Thirty-year trends in outcomes of percutaneous coronary interventions in diabetic patients

OBJECTIVE

To characterize in-hospital and long-term outcomes after percutaneous coronary interventions (PCIs) in patients with diabetes mellitus (DM).

PATIENTS AND METHODS

Patients who underwent PCIs were grouped by era: group 1, October 9, 1979, to December 31, 1989 (408 with DM and 2684 without DM); group 2, January 1, 1990, to December 31, 1996 (1170 and 4664); group 3, January 1, 1997, to December 31, 2003 (2032 and 6584); and group 4, January 1, 2004, to December 31, 2008 (1412 and 4141). The main outcome measures were in-hospital mortality, major adverse cardiovascular events, long-term mortality, composites of mortality with revascularization, and ischemic events.

RESULTS

Patients with DM had significant declines in in-hospital adverse outcomes over time. These declines were similar to those observed in patients without DM. After adjusting for baseline risk, there was no significant change in the association between DM and in-hospital death or in-hospital major adverse cardiovascular events over time. The use of aspirin, β-blockers, angiotensin-converting enzyme inhibitors, lipid-lowering drugs, and thienopyridines all increased over time. The effect of DM on long-term survival and survival free of revascularization did not change significantly from group 2 to group 4. However, the effect of DM on survival free of myocardial infarction and stroke was reduced significantly, from a hazard ratio (95% CI) of 1.71 (1.51-1.92) in group 2 to 1.39 (1.20-1.60) in group 4 (P=.04).

CONCLUSION

Over 30 years, the improving outcomes in patients with diabetes who underwent PCIs have been similar to improvements in patients without DM. However, the risk-adjusted association of DM with long-term death, myocardial infarction, and stroke has decreased in the current era (group 4) compared with the bailout stent era (group 2).

Risk of death and myocardial infarction in patients with peripheral arterial disease undergoing percutaneous coronary intervention (from the National Heart, Lung and Blood Institute Dynamic Registry)

Patients with peripheral arterial disease (PAD) undergoing percutaneous coronary intervention (PCI) are at high risk for adverse cardiovascular events. Trends over time in outcomes with advances in PCI and medical therapy are unknown. We evaluated 866 patients with PAD in the National Heart, Lung, and Blood Institute (NHLBI) Dynamic Registry undergoing PCI according to treatment eras: the early bare metal stent (BMS) era (wave 1, 1997 to 1998, n = 180), the BMS era (waves 2 and 3, 1999 and 2001 to 2002, n = 339), and the drug-eluting stent (DES) era (waves 4 and 5, 2004 and 2006, n = 347). We compared in-hospital and 1-year outcomes by recruitment era. In-hospital coronary artery bypass graft surgery rates were significantly lower in the later eras (3.9%, 0.9%, and 0.6% for the early BMS, BMS, and DES eras, respectively, p for trend = 0.005), and an increasing percentage of patients were discharged on aspirin, β blockers, statins, and thienopyridines (p for trend <0.001 for all comparisons). Cumulative 1-year event rates in patients with PAD in the early BMS era, BMS era, and DES era for death were 13.7%, 10.5%, and 9.8% (p for trend = 0.21), those for myocardial infarction (MI) were 9.8%, 8.8%, and 10.0% (p for trend = 0.95), and those for repeat revascularization were 26.8%, 21.0%, and 17.2% (p for trend = 0.008). The 1-year adjusted hazard ratios of adverse events in patients with PAD using the early BMS era as the reference were 0.84 for death in the BMS era (95% confidence interval [CI] 0.46 to 1.55, p = 0.58) and 1.35 in the DES era (95% CI 0.71 to 2.56, p = 0.36), 0.89 for MI in the BMS era (95% CI 0.48 to 1.66, p = 0.72) and 1.02 in the DES era (95% CI 0.55 to 1.87, p = 0.95), and 0.63 for repeat revascularization in the BMS era (95% CI 0.41 to 0.97, p = 0.04) and 0.46 in the DES era (95% CI 0.29 to 0.73, p = 0.001). In conclusion, despite significant improvements in medical therapy and a decrease in repeat revascularization over time, patients with PAD who undergo PCI have a persistent high rate of death and MI.

Early invasive versus conservative strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) two strategies are possible, either a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially, with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 1), MEDLINE and EMBASE were searched (1996 to February 2008) with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified five studies (7818 participants). Using intention-to-treat analysis with random-effects models, summary estimates of relative risk (RR) with 95% confidence interval (CI) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction, all-cause death or non-fatal myocardial infarction, and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using Chi(2) and variance (I(2) statistic) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy (RR 1.59, 95% CI 0.96 to 2.64). The invasive strategy did not reduce death on longer-term follow up. Myocardial infarction rates assessed at 6 to 12 months (5 trials) and 3 to 5 years (3 trials) were significantly decreased by an invasive strategy (RR 0.73, 95% CI 0.62 to 0.86; and RR 0.78, 95% CI 0.67 to 0.92 respectively). The incidence of early (< 4 month) and intermediate (6 to 12 month) refractory angina were both significantly decreased by an invasive strategy (RR 0.47, 95% CI 0.32 to 0.68; and RR 0.67, 95% CI 0.55 to 0.83 respectively), as were early and intermediate rehospitalization rates (RR 0.60, 95% CI 0.41to 0.88; and RR 0.67, 95% CI 0.61 to 0.74 respectively). The invasive strategy was associated with a two-fold increase in the RR of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the RR of (minor) bleeding with no hazard of stroke.

AUTHORS' CONCLUSIONS

Compared to a conservative strategy for UA/NSTEMI, an invasive strategy is associated with reduced rates of refractory angina and rehospitalization in the shorter term and myocardial infarction in the longer term. However, the invasive strategy is associated with a doubled risk of procedure-related heart attack and increased risk of bleeding and procedural biomarker leaks. Available data suggest that an invasive strategy may be particularly useful in those at high risk for recurrent events.

Trends in the Association Between Age and In-Hospital Mortality After Percutaneous Coronary Intervention

Background— Temporal trends and contemporary data characterizing the impact of patient age on in-hospital outcomes of percutaneous coronary interventions are lacking. We sought to determine the importance of age by assessing the in-hospital mortality of stratified age groups in the National Cardiovascular Data Registry.

Methods and Results— In-hospital mortality after percutaneous coronary intervention on 1 410 069 patients was age stratified into 4 groups—group 1 (age <40, n=25 679), group 2 (40 to 59, n=496 204), group 3 (60 to 79, n=732 574), and group 4 (≥80, n=155 612)—admitted from January 1, 2001, to December 31, 2006. Overall in-hospital mortality was 1.22%; in-hospital mortality was 0.60%, 0.59%, 1.26%, and 3.16% in groups 1 to 4, respectively, P <0.0001. Overall temporal improvement per calendar year in the adjusted in-hospital mortality after percutaneous coronary intervention was noted in most groups; however, this finding was significant only in the 2 older age groups, group 3 (odds ratio, 0.94; 95% CI, 0.92 to 0.96) and group 4 (odds ratio, 0.95; 95% CI, 0.92 to 0.97). The absolute mortality reduction was greatest in the most elderly group, those over the age of 80 years.

Conclusions— In-hospital mortality after percutaneous coronary intervention has fallen for all age groups over the past 6 years. However, the largest absolute reduction was seen among patients 80 years of age or older.

Early invasive versus conservative strategies for unstable angina & non-ST-elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST-elevation myocardial infarction (UA/NSTEMI) two strategies are possible: a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to a conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (Issue 3 2005), MEDLINE and EMBASE were searched from 1996 to September 2005 with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified 5 studies (7818 participants). Using intention-to-treat analysis with random effects models, summary estimates of relative risk (95% confidence interval [CI]) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction; all-cause death or non-fatal myocardial infarction; and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using chi-square and variance (I(2)) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy; relative risk 1.59 (95% CI 0.96 to 2.64). Mortality and myocardial infarction assessed at 2-5 years in two trials were significantly decreased by an invasive strategy with relative risk of 0.75 (95% CI 0.62 to 0.92) and 0.75 (95% CI 0.61 to 0.91) respectively. The composite end-point of death or non-fatal myocardial infarction was significantly decreased by an invasive strategy at several time points after initial hospitalization. The incidence of early (<4 months) and intermediate (6-12 months) refractory angina were both significantly decreased by an invasive strategy; relative risk 0.47 (95% CI 0.32 to 0.68) and 0.67 (95% CI 0.55 to 0.83) respectively, as were early and intermediate rehospitalization rates with relative risk 0.60 (95% CI 0.41 to 0.88) and 0.67 (95% CI 0.61 to 0.74) respectively. The invasive strategy was associated with a two-fold increase in the relative risk of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the relative risk of bleeding.

AUTHORS' CONCLUSIONS

An early invasive strategy is preferable to a conservative strategy in the treatment of UA/NSTEMI.

Rationale for the revascularization arm of the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) Trial

Modern coronary revascularization therapies, coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI), continue to evolve and are widely applied. However, for patients with mild stable angina, or those who are asymptomatic with angiographically documented coronary artery disease (CAD), no survival benefit or reduction in the incidence of myocardial infarction has been demonstrated with CABG or PCI, except in the case of subgroups with angiographically determined high risk due to extensive multivessel disease with depressed LV function or left main CAD. At the same time, medical therapy continues to advance, with demonstrable benefit in both primary and secondary prevention of atherosclerotic coronary disease events. Patients with type 2 diabetes mellitus, at increased risk for adverse cardiac events, have been shown to benefit from these approaches as well. However, in asymptomatic or mildly symptomatic patients with documented ischemia and angiographically significant CAD, the incremental benefit-or hazard-associated with early revascularization superimposed on aggressive medical and risk factor modification therapies is unknown. We discuss the background and rationale for investigating the impact of early revascularization in patients with diabetes and CAD.

Emergency Coronary Artery Bypass Surgery for Percutaneous Coronary Interventions

OBJECTIVES

The purpose of the current study was to evaluate the changes in incidence, clinical characteristics, and indications for emergency coronary artery bypass grafting (CABG) in patients undergoing percutaneous coronary intervention (PCI) from 1979 to 2003.

BACKGROUND

Emergency CABG after PCI is associated with significant morbidity and mortality.

METHODS

Data from 23,087 patients who underwent PCI at Mayo Clinic from 1979 to 2003 were analyzed. Patients were divided into three groups: the "pre-stent" era, 1979 to 1994 (n = 8,905); the "initial stent era," 1995 to 1999 (n = 7,605); and the "current stent era," 2000 to 2003 (n = 6,577).

RESULTS

Although patients undergoing PCI in the recent time periods had more high-risk features, there was a significant decrease in the incidence of emergency CABG from 2.9% to 0.7% to 0.3% across the groups (p < 0.001). Patients requiring emergency surgery in the recent time periods had a higher prevalence of hypertension, prior revascularization, and left ventricular dysfunction (ejection fraction <40%), as well as more complex coronary lesions. Fewer patients in the current stent era had coronary artery dissections and abrupt vessel closure requiring emergency CABG. The in-hospital mortality rate for emergency CABG patients remains unchanged and ranges from 10% to 14%.

CONCLUSIONS

The current study demonstrates that despite the increase in high-risk patients undergoing PCI, there has been a marked decrease in the incidence of patients requiring emergency CABG. However, the in-hospital mortality rate for those requiring emergency CABG remains high and unchanged.

Integrated Management of Patients with Diabetes Mellitus and Ischemic Heart Disease: PCI, CABG, and Medical Therapy

Modern coronary revascularization strategies are based on studies performed in the 1970s and 1980s that compared coronary artery bypass surgery with standard medical therapy available at the time. Studies comparing surgical and percutaneous revascularization followed, demonstrating similar long-term outcome among thousands of randomized patients. The largest of these trials, the Bypass Angioplasty Revascularization Investigation (BARI), cast doubt on the generalizability of these findings to all subgroups, finding that patients with diabetes mellitus and multivessel disease had worse long-term outcome with an initial strategy of percutaneous transluminal coronary angioplasty (PTCA). Indeed, patients with diabetes mellitus are at increased risk for cardiovascular morbidity and mortality, while the benefit of standard therapies in these patients is attenuated by the underlying metabolic abnormalities and significant comorbidities associated with the diabetic state. However, surgical and percutaneous revascularization techniques continue to evolve. Similarly, modern medical therapy is markedly superior to that available during these early studies, with demonstrable benefit in primary and secondary prevention of vascular events in both diabetic and nondiabetic patients. Ongoing trials will define the impact of current treatment modalities in this important and growing population.

Silicon carbide-coated stents in patients with acute coronary syndrome

Silicon carbide (aSIC-C) is a stent coating with antithrombogenic as well as anti-inflammatory properties as compared with uncoated stainless steal based on in vitro and in vivo studies. This study investigated the potential of this coating in patients with unstable angina. At 38 study sites, 485 patients were randomized to an aSIC-C (n = 238) or a conventional stainless steal stent (n = 247). Patient were classified according to angina at rest within last 48 hr to Braunwald in class IIB (= 314) and IIIB (n = 171). The primary endpoint was a combination of death, myocardial infarction, or ischemia-driven target vessel revascularization at 6 months. Complications of procedures performed at 0.4 +/- 1.1 days after admission occurred at lower rates than previously reported in this high-risk population, but the primary endpoint was not different between the study groups. Only in Braunwald class IIIB patients did the primary endpoint occur less frequently in patients with an aSIC-C stent as compared to patients with a conventional stent (5.8% vs. 15.3%; P = 0.049). At 9-month follow-up, the level of difference was maintained, but statistical significance was lost. Quantitative angiography revealed no significant difference between the stents in the subgroups. This study suggests that aSIC-C stents exert clinically measurable effects in patients with unstable angina with recent symptoms at rest. This coating deserves further clinical investigation and may serve as platform for antiproliferative drugs.

Impact of delays to cardiac surgery after failed angioplasty and stenting

OBJECTIVES

This study was designed to determine the likelihood of harm in patients having additional delays before urgent coronary artery bypass graft (UCABG) surgery after percutaneous coronary intervention (PCI).

BACKGROUND

Patients who have PCI at hospitals without cardiac surgery have additional delays to surgery when UCABG is indicated.

METHODS

Detailed chart review was performed on all patients who had a failed PCI leading to UCABG at a large tertiary care hospital. A prespecified set of criteria (hemodynamic instability, coronary perforation with significant effusion or tamponade, or severe ischemia) was used to identify patients who would have an increased likelihood of harm with additional delays to surgery.

RESULTS

From 1996 to 2000, 6,582 PCIs were performed. There were 45 patients (0.7%) identified to have UCABG. The demographic characteristics of the UCABG patients were similar to the rest of the patients in the PCI database, except for significantly more type C lesions (45.3% vs. 25.0%, p < 0.001) and more urgent cases (66.6% vs. 49.8%, p = 0.03) in patients with UCABG. Myocardial infarction occurred in eight patients (17.0%) after UCABG, with a mean peak creatine kinase of 2,445 +/- 1,212 IU/l. Death during the index hospital admission occurred in two patients. Eleven of the 45 patients (24.4%) were identified by the prespecified criteria to be at high likelihood of harm with additional delays to surgery. The absolute risk of harm is approximately one to two patients per 1,000 PCIs.

CONCLUSIONS

Approximately one in four patients referred for UCABG would be placed at increased risk of harm if delays to surgery were encountered.

Clinical evaluation of coronary lesion characteristics in acute myocardial infarction

Coronary lesion instability at the onset of acute myocardial infarction (AMI) was evaluated. The mechanism of AMI has been considered to be coronary lesion instability with occlusive thrombus, although more than one half of AMI occurs in clinically stable patients. A total of 313 AMI patients treated by primary percutaneous transluminal coronary angioplasty with provisional stenting (rate, 41%) were studied. They were divided into 2 groups: group 1A (n = 211), without unstable angina before AMI onset, and group 1B (n = 102), with unstable angina before onset. Moreover, angina patients treated similarly were studied: group 2A (n = 180), with stable angina, and group 2B (n = 204), with unstable angina. Coronary lesion instability at AMI onset was also predicted by C-reactive protein (CRP) levels within 6 hours after onset, before they were affected by myocardial damage. The incidence of repeated AMI and/or target vessel revascularization was 1.9% in group 1A, 7.8% in 1B (p=0.035), 1.7% in 2A, and 5.9% in 2B (p=0.043). Event-free survival curves were consistent with each other in groups 1A and 2A and in groups 1B and 2B. CRP levels on admission were 2.0 +/- 1.7 mg/L in group 1A, 3.3 +/- 4.8 mg/L in group 1B (p<0.001), 2.1 +/- 1.7 mg/L in group 2A, and 3.4 +/- 4.7 mg/L in group 2B (p<0.001). Thus coronary lesion characteristics at AMI onset appeared to be similar in groups 1A and 2A and in groups 1B and 2B. A substantial number of patients have stable culprit lesions at the onset of AMI.

Correlates of procedural complications and a simple integer risk score for percutaneous coronary intervention

OBJECTIVES

Our goals were to identify clinical and angiographic risk factors associated with major cardiovascular complications of percutaneous coronary intervention (PCI) (in-hospital death, Q-wave myocardial infarction, urgent or emergent coronary artery bypass surgery and stroke) and to construct a simple score for risk stratification.

BACKGROUND

Both clinical and angiographic features influence risk of PCIs.

METHODS

Percutaneous coronary interventions performed between January 1, 1996, and December 31, 1999, were analyzed. Logistic regression and bootstrap methods were used to create an integer risk score for estimating the risk of procedural complications using baseline, angiographic and procedural characteristics. The risk score was tested in a validation-set consisting of all procedures performed in the year 2000.

RESULTS

Among 5,463 procedures, 5 clinical and 3 angiographic variables were significantly correlated with procedural complications: cardiogenic shock, left main coronary artery disease, severe renal disease, urgent or emergent procedure, congestive heart failure class III or higher, thrombus, multivessel disease and older age. In the validation-set, the model fitted the data adequately; the average receiver operating characteristic curve area was 0.782 (standard deviation, 0.018).

CONCLUSIONS

Eight variables were combined into a convenient bedside risk scoring system that estimates the risk of complications after PCIs.

Rationale for on-site cardiac surgery for primary angioplasty: a time for reappraisal

Since the early 1990s, with significant improvement in the procedural success of percutaneous coronary interventions (PCIs), there has been a concomitant reduction in the need for emergency coronary artery bypass graft surgery. This review article focuses on the need for on-site cardiac surgery in patients with acute myocardial infarction undergoing primary angioplasty at centers without on-site cardiac surgical backup. It gives an overview of the need for emergency bypass surgery in both the large trial setting and the community hospital setting. Special consideration is also given to the risks and benefits of primary angioplasty compared with thrombolytic therapy, transfer to an institution with an on-site cardiac surgical facility compared with primary PCI, the frequency and indications for emergency cardiac surgery related and unrelated to primary angioplasty and the requirements for primary angioplasty that must be met in hospitals without the capability of on-site cardiac surgery.

Interventional therapy of the acute coronary syndromes

The acute coronary syndromes (ACS) have in common rupture of a vulnerable plaque, leading to exposure of the subendothelial surface and plaque core. The resultant thrombosis leads to a variable degree of flow occlusion, the extent of which differentiates the three syndromes and their treatment by percutaneous coronary intervention (PCI). The guiding principle in the decision when to use PCI in the ACS is that the more time critical and high risk the clinical situation, the more likely it is that PCI will improve ultimate outcome. The use of risk stratification by clinical variables can lead to better triage of patients with non-ST-elevation myocardial infarction (MI) and unstable angina between PCI and medical management. Patients presenting with symptoms suggestive of prolonged ischemia should have an electrocardiogram searching for ST changes, a targeted physical, and blood drawn for rapid assay of cardiac enzymes. In the event that ST elevations suggest infarction, while medical therapy is initiated, emergency cardiac catheterization can be organized. PCI in ACS requires adjunctive antiplatelet and antithrombin therapy, and, in general, coronary stenting is advisable. Among patients with non-ST-elevation MI or unstable angina who can be medically stabilized, the presence of high clinical risk scores would favor early coronary angiography. In their absence, medical therapy can be pursued, unless recurrent ischemia occurs. When the patient's condition is stable, evaluation by stress testing can be used to guide further decisions.

Early coronary angiography improves long-term survival in unstable angina

BACKGROUND

The role of early coronary angiography in the evaluation of patients with unstable angina has been controversial. This study was designed to determine the effect of early coronary angiography on long-term survival in patients with unstable angina.

METHODS

We reviewed the Olmsted County Acute Chest Pain Database, a population-based epidemiologic registry that includes all patients residing within Olmsted County who were seen for emergency department evaluation of acute chest pain from 1985 to 1992. Patients with symptoms consistent with myocardial ischemia qualifying as unstable angina were classified as undergoing early (</=7 days of index presentation) angiography or not.

RESULTS

A total of 2264 patients with symptoms consistent with unstable angina were identified with a mean duration of follow-up of 6 years; 892 underwent early angiography. Early angiography patients were younger; less likely to have heart failure; more likely to be male, hypercholesterolemic, and smokers; had prior coronary revascularization; and had a myocardial infarction at the index presentation. After baseline differences were controlled, early angiography was associated with a reduction in all-cause long-term mortality (relative risk 0.63, 95% CI 0.53-0.74). Patients at intermediate or high risk for death or myocardial infarction at presentation were most likely to benefit from early angiography.

CONCLUSION

Early angiography in the evaluation of patients with unstable angina was associated with a reduction in all-cause mortality, particularly in intermediate- and high-risk patients, in this retrospective population-based study.