|Year : 2008 | Volume
| Issue : 3 | Page : 96-99
|Date of Web Publication||17-Jun-2010|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
. Cardiovascular News. Heart Views 2008;9:96-9
Long-Term Safety and Efficacy of Percutaneous Coronary Intervention with Stenting and Coronary Artery Bypass Surgery for Multivessel Coronary Artery Disease
A pooled analysis of 3051 patients was performed in 4 randomized trials evaluating the relative safety and efficacy of PCI with stenting and CABG at 5 years for the treatment of multivessel coronary artery disease. The primary end point was the composite end point of death, stroke, or myocardial infarction. The secondary end point was the occurrence of major adverse cardiac and cerebrovascular accidents, death, stroke, myocardial infarction, and repeat revascularization. Heterogeneities were tested in treatment effect in patient subgroups.
At 5 years, the cumulative incidence of death, myocardial infarction, and stroke was similar in patients randomized to PCI with stenting versus CABG (16.7% versus 16.9%, respectively; hazard ratio, 1.04, 95% confidence interval, 0.86 to 1.27; P = 0.69). Repeat revascularization, however, occurred significantly more frequently after PCI than CABG (29.0% versus 7.9%, respectively; hazard ratio, 0.23; 95% confidence interval, 0.18 to 0.29; P < 0.001). Major adverse cardiac and cerebrovascular events were significantly higher in the PCI than the CABG group (39.2% versus 23.0%, respectively; hazard ratio, 0.53; 95% confidence interval, 0.45 to 0.61; P < 0.001). No heterogeneity of treatment effect was found in the subgroups, including diabetic patients and those presenting with 3-vessel disease.
In this pooled analysis of 4 randomized trials, PCI with stenting was associated with a long-term safety profile similar to that of CABG. However, as a result of persistently lower repeat revascularization rates in the CABG patients, overall major adverse cardiac and cerebrovascular event rates were significantly lower in the CABG group at 5 years.
Drug-Eluting Versus Bare Metal Stents in Patients With ST-Segment-Elevation Myocardial Infarction
We randomly assigned 626 patients referred within 12 hours from symptom onset of an ST-elevation myocardial infarction to have a DES or a bare metal stent implanted in the infarct-related lesion with or without distal protection during primary percutaneous coronary intervention. Quantitative coronary angiography was performed during the index treatment and 8 months later. The primary end point was loss of the lumen diameter in the infarct-related lesion induced by neointimal proliferation.
Patients were comparable with regard to baseline demographic and angiographic characteristics. The mean late lumen loss was significantly lower in patients treated with a DES (0.06 mm; SD, 0.66 mm) than in patients who had a bare metal stent implanted (0.47 mm; SD, 0.69 mm; P < 0.001). The rate of the composite end point of cardiac death, recurrent myocardial infarction, and target lesion revascularization was 8.6% in the DES group versus 14.4% in the bare metal stent group (P = 0.03). Cardiac death occurred in 4.2% and 1.6% of the patients (P = 0.09) and stent thrombosis occurred in 2.0% and 2.6% (P = 0.72), respectively.
Implantation of DES improves the angiographic outcome and need for repeat revascularization without increasing the short-term risk of stent thrombosis but has a tendency to increase cardiac death in patients with ST-segment-elevation myocardial infarction.
Impact of In-Hospital Revascularization on Survival in Patients with Non-ST-Elevation Acute Coronary Syndrome and Congestive Heart Failure
Patients with non-ST-elevation acute coronary syndrome complicated by congestive heart failure (CHF) have a poor prognosis. The aims of this study were to describe the use of revascularization in non-ST-elevation acute coronary syndrome and CHF and to analyze its impact on survival.
In the Global Registry of Acute Coronary Events, 29 844 patients with non-ST-elevation acute coronary syndrome were enrolled at 120 hospitals in 14 countries between April 1999 and June 2007; 4953 had CHF at presentation. One fifth of the patients with CHF underwent revascularization versus 35% of those without CHF (P < 0.001). Among CHF patients, revascularized patients had lower-risk baseline clinical characteristics than nonrevascularized patients and were more likely to receive evidence-based cardiac medications. Hospital rates were not affected by revascularization (adjusted hazard ratio 0.97, 95% confidence interval 0.72 to 1.33, P = 0.87). Death from discharge to 6-month follow-up was lower in patients who underwent revascularization than in those who did not (odds ratio 0.51, 95% confidence interval 0.35 to 0.74, P < 0.001).
This difference persisted after adjustment for GRACE risk score variables, country, and propensity for revascularization (odds ratio 0.58, 95% confidence interval 0.40 to 0.85, P = 0.005). When revascularization as a time-varying covariate was taken into account in an adjusted Cox regression, the rate of death was again lower in patients undergoing revascularization (hazard ratio 0.64, 95% confidence interval 0.45 to 0.93, P = 0.02).
This observational study suggests a low use of in-hospital revascularization in non-ST-elevation acute coronary syndrome patients with CHF. The consistent reduction in postdischarge death in revascularized patients suggests that broader application of revascularization in this high-risk group may be beneficial.
Drug-Eluting or Bare-Metal Stenting in Patients with Diabetes Mellitus Results from the Massachusetts Data Analysis Center Registry
Patients with diabetes mellitus (DM) are at high risk for restenosis, myocardial infarction, and cardiac mortality after coronary stenting, and the long-term safety of drug-eluting stents (DES) relative to bare-metal stents (BMS) in DM is uncertain. Investigators report on a large consecutive series of patients with DM followed up for 3 years after DES and BMS from a regional contemporary US practice with mandatory reporting.
All adults with DM undergoing percutaneous coronary intervention with stenting between April 1, 2003, and September 30, 2004, at all acute care nonfederal hospitals in Massachusetts were identified from a mandatory state database. According to index admission stent type, patients were classified as DES treated if all stents were drug eluting and as BMS treated if all stents were bare metal; patients treated with both types of stents were excluded from the primary analysis. Mortality rates were obtained from vital statistics records, and myocardial infarction and revascularization rates were obtained from the state database with complete 3 years of follow-up on the entire cohort.
Risk-adjusted mortality, myocardial infarction, and revascularization differences (DES-BMS) were estimated with propensity-score matching based on clinical, procedural, hospital, and insurance information collected at the index admission. DM was present in 5051 patients (29% of the population) treated with DES or BMS during the study. Patients with DM were more likely to receive DES than BMS (66.1% versus 33.9%; P < 0.001). The unadjusted cumulative incidence of mortality at 3 years was 14.4% in DES versus 22.2% in BMS (P < 0.001). Based on propensity-score analysis of 1:1 matched DES versus BMS patients (1476 DES:1476 BMS), the risk-adjusted mortality, MI, and target vessel revascularization rates at 3 years were 17.5% versus 20.7% (risk difference, -3.2%; 95% confidence interval, -6.0 to -0.4; P = 0.02), 13.8% versus 16.9% (-3.0%; 95% confidence interval, -5.6 to 0.5; P = 0.02), and 18.4% versus 23.7% (-5.4%; confidence interval, -8.3 to -2.4; P < 0.001), respectively.
In a real-world diabetic patient population with mandatory reporting and follow-up, DES were associated with reduced mortality, myocardial infarction, and revascularization rates at long-term follow-up compared with BMS.
Pilot Study to Assess the Influence of β-Blockade on Mitral Regurgitant Volume and Left Ventricular Work in Degenerative Mitral Valve Disease
A medical treatment that decreases the likelihood of left ventricular (LV) dysfunction or symptoms would benefit patients with moderate to severe degenerative mitral regurgitation. The aim of this pilot study was to determine the short-term effects of a β-blocker on mitral regurgitant volume and LV work in these patients.
Twenty-five patients with moderate or severe degenerative mitral regurgitation were randomized in a double-blind crossover study to the b1-selective adrenergic blocker metoprolol (mean daily dose, 119 mg; range 23.75 to 190 mg) and placebo for 14 ± 3 days. At the end of each treatment period, ascending aortic flow and LV stroke volume were measured by cardiac magnetic resonance imaging, and mitral regurgitant volume was calculated.
On β-blocker, heart rate decreased from 65 ± 10 by 10 ± 7 bpm (mean ± SD) and systolic blood pressure decreased from 138 ± 18 by 16 ± 12 mm Hg (P < 0.0001 for both). No significant change occurred in LV ejection fraction (from 65 ± 5%; change, -0.6 ± 2.7%; P = 0.3) or mitral regurgitant volume (from 59 ± 36 mL; change, 3 ± 13 mL; P = 0.3), but forward stroke volume increased from 89 ± 21 by 5 ± 11 mL (P = 0.03). Because heart rate was lower on metoprolol, cardiac output decreased from 5.68 ± 1.04 by 0.56 ± 0.78 L/min (P = 0.001), but a greater decrease occurred in LV output, from 9.51 ± 2.22 by 1.30 ± 1.08 L/min (P < 0.0001). Mitral regurgitant volume per minute decreased from 3.83 ± 2.41 by 0.74 ± 1.00 L/min (P = 0.001). The decrease in LV work on β-blocker (mean, 21%; 95% confidence interval, 15 to 27) was greater (P = 0.001) than the decrease in cardiac output (mean, 9%; 95% confidence interval, 3 to 15).
In this pilot study, short-term treatment with a β-blocker did not change mitral regurgitant volume per beat but decreased LV work in patients with moderate to severe degenerative mitral regurgitation. Further research is needed to determine whether longer-term treatment with β-blockers will decrease progressive LV dysfunction and symptomatic deterioration.
Delayed Arterial Healing and Increased Late Stent Thrombosis at Culprit Sites After Drug-Eluting Stent Placement for Acute Myocardial Infarction Patients: An Autopsy Study
The long-term safety of drug-eluting stents (DES) for acute myocardial infarction (AMI) remains uncertain. Using autopsy data, we evaluated the pathological responses of the stented segment in patients treated with DES for AMI and compared with patients with stable angina.
From the CV Path Registry of 138 DES autopsies, we identified 25 patients who presented with AMI and had an underlying necrotic core with a ruptured fibrous cap. Twenty-six patients who had stable angina with thick-cap fibroatheroma treated by DES were selected as controls. Histomorphometric analysis was performed in patients with > 30-day stent duration. We compared the response to stenting at the culprit site in these 2 groups and to nonculprit sites within each stent. Late stent thrombosis was significantly less frequent in stable (11%) than in AMI (41%; P = 0.04) patients. Although neointimal thickness in the AMI culprit site was significantly less (median, 0.04 mm; interquartile range [IQR], 0.02 to 0.09 mm), the prevalence of uncovered struts (49%; IQR, 16% to 96%), fibrin deposition (63 ± 28%), and inflammation (35%; IQR, 27% to 49%) were significantly greater compared with the culprit site in stable patients (neointimal thickness: 0.11 mm [IQR, 0.07 to 0.21 mm], P = 0.008; uncovered struts: 9% [IQR, 0% to 39%], P = 0.01; fibrin: 36 ± 27%, P = 0.008; inflammation, 17% [IQR, 7% to 25%], P = 0.003) and the nonculprit site within each stent.
Vessel healing at the culprit site in AMI patients treated with DES is substantially delayed compared with the culprit site in patients receiving DES for stable angina, emphasizing the importance of underlying plaque morphology in the arterial response to DES. Our data suggest an increased risk of thrombotic complications in patients treated with DES for AMI.
Association Between Intraoperative and Early Postoperative Glucose Levels and Adverse Outcomes After Complex Congenital Heart Surgery
Investigators sought to determine whether associations exist between perioperative glucose exposure, prolonged hospitalization, and morbid events after complex congenital heart surgery.
Metrics of glucose control, including average, peak, minimum, and SD of glucose levels, and duration of hyperglycemia were determined intraoperatively and for 72 hours after surgery for 378 consecutive high-risk cardiac surgical patients. Multivariable regression analyses were used to determine relationships between these metrics of glucose control, hospital length of stay, and a composite morbidity-mortality outcome after controlling for multiple variables known to influence early outcomes after congenital heart surgery. Intraoperatively, a minimum glucose 75 mg/dL was associated with greater adjusted odds of reaching the composite morbidity-mortality end point (odds ratio [OR], 3.10; 95% confidence interval [CI], 1.49 to 6.48), but other metrics of glucose control were not associated with the composite end point or length of stay. Greater duration of hyperglycemia (glucose >126 mg/dL) during the 72 postoperative hours was associated with longer duration of hospitalization (P<0.001). In the 72 hours after surgery, average glucose <110 mg/dL (OR, 7.30; 95% CI, 1.95 to 27.25) or >143 mg/dL (OR, 5.21; 95% CI, 1.37 to 19.89), minimum glucose 75 mg/dL (OR, 2.85; 95% CI, 1.38 to 5.88), and peak glucose level 250 mg/dL (OR, 2.55; 95% CI, 1.20 to 5.43) were all associated with greater adjusted odds of reaching the composite morbidity-mortality end point.
In children undergoing complex congenital heart surgery, the optimal postoperative glucose range may be 110 to 126 mg/dL. Randomized trials of strict glycemic control achieved with insulin infusions in this patient population are warranted.
Exercise-Induced Pulmonary Arterial Hypertension
The clinical relevance of exercise-induced pulmonary arterial hypertension (PAH) is uncertain, and its existence has never been well studied by direct measurements of central hemodynamics. Using invasive cardiopulmonary exercise testing, we hypothesized that exercise-induced PAH represents a symptomatic stage of PAH, physiologically intermediate between resting pulmonary arterial hypertension and normal.
A total of 406 consecutive clinically indicated cardiopulmonary exercise tests with radial and pulmonary arterial catheters and radionuclide ventriculographic scanning were analyzed. The invasive hemodynamic phenotype of exercise-induced PAH (n = 78) was compared with resting PAH (n = 15) and normals (n = 16). Log-log plots of mean pulmonary artery pressure versus oxygen uptake (VO2) were obtained, and a "join-point" for a least residual sum of squares for 2 straight-line segments (slopes m1, m2) was determined; m2 < m1 = "plateau," and m2 < m1 = "takeoff" pattern. At maximum exercise, O2 (55.8±20.3% versus 66.5 ± 16.3% versus 91.7 ± 13.7% predicted) was lowest in resting PAH, intermediate in exercise-induced PAH, and highest in normals, whereas mean pulmonary artery pressure (48.4 ± 11.1 versus 36.6 ± 5.7 versus 27.4 + 3.7 mm Hg) and pulmonary vascular resistance (294±158 versus 161 ± 60 versus 62±20 dyne·s·cm-5, respectively; P < 0.05) followed an opposite pattern. An exercise-induced PAH plateau (n = 32) was associated with lower O2max (60.6 ± 15.1% versus 72.0 ± 16.1% predicted) and maximum cardiac output (78.2 ± 17.1% versus 87.8 ± 18.3% predicted) and a higher resting pulmonary vascular resistance (247 ±1 01 versus 199 ± 56 dyne·s ·cm-5; P < 0.05) than takeoff (n = 40). The plateau pattern was most common in resting PAH, and the takeoff pattern was present in nearly all normals.
Exercise-induced PAH is an early, mild, and clinically relevant phase of the PAH spectrum.
Antithrombotic Therapy with Fondaparinux in Patients with ST-and Non-ST-Segment Elevation Acute Coronary Syndromes (OASIS 5 and 6)
The Fifth and Sixth Organization to Assess Strategies in Ischemic Syndromes (OASIS 5 and 6) trials evaluated fondaparinux, a synthetic factor Xa inhibitor, in patients with non-ST- and ST-segment elevation acute coronary syndromes, respectively. Combined results for these 2 trials on major efficacy and safety outcomes and data on the effects of fondaparinux in relation to interventional management strategy have not been previously reported.
Investigators performed an individual patient-level combined analysis of 26 512 patients from the OASIS 5 and 6 trials who were randomized in a double-blind fashion to fondaparinux 2.5 mg daily or a heparin-based strategy (dose-adjusted unfractionated heparin or enoxaparin). Results were stratified according to whether an early invasive, a delayed invasive, or an initial conservative management strategy was performed. Fondaparinux was superior to heparin in reducing the composite of death, myocardial infarction, or stroke (8.0% versus 7.2%; hazard ratio [HR], 0.91; P=0.03) and death alone (4.3% versus 3.8%; HR, 0.89; P=0.05). Fondaparinux reduced major bleeding by 41% (3.4% versus 2.1%; HR, 0.59; P<0.00001) and had a more favorable net clinical outcome than heparin (11.1% versus 9.3%; HR, 0.83; P<0.0001). In 19 085 patients treated with an invasive strategy, fondaparinux suppressed ischemic events to an extent similar to heparin and reduced major bleeding by more than one-half, resulting in a superior net clinical outcome (10.8% versus 9.4%; HR, 0.87; P=0.008). A similar benefit also was observed in those treated with a conservative strategy (HR, 0.74; 95% confidence interval, 0.64 to 0.85; P<0.001).
Compared with a heparin-based strategy, fondaparinux reduced mortality, ischemic events, and major bleeding across the full spectrum of acute coronary syndromes and was associated with a more favorable net clinical outcome in patients undergoing either an invasive or a conservative management strategy.
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