Heart Arrhythmias Increase Mortality in Catheterizations

Tachycardia or fibrillation associated with higher 90-day mortality following coronary interventions

06 may 2009-- The incidence of ventricular tachycardia or fibrillation (VT/VF) during and after percutaneous coronary intervention (PCI) is associated with higher death rates within 90 days, according to a study published in the May 6 issue of the Journal of the American Medical Association.

Rajendra H. Mehta, M.D., of the Duke Clinical Research Institute in Durham, N.C., and colleagues studied 5,745 patients with ST-elevation myocardial infarction (STEMI) who underwent PCI at 296 hospitals in 17 countries from 2004 to 2006. The group, drawn from the Assessment of Pexelizumab in Acute Myocardial Infarction trial, was sorted into the following four subgroups related to VT/VF: no episode of VT/VF; VT/VF at any time; early VT/VF (before completion of cardiac catheterization); and late VT/VF (after completion of cardiac catheterization). Study outcome was mortality at 90 days.

The researchers found that VT/VF occurred in 329 STEMI patients, 64 percent of those episodes occurring before the end of catheterization, and 90 percent occurring within 48 hours of presentation with STEMI symptoms. Ninety-day mortality was worse in those who had VT/VF compared to those who did not (23.2 percent versus 3.6 percent), and was worse yet for those in whom VT/VF occurred late (33.3 percent) versus early (17.2 percent). The hazards ratios for late and early VT/VF compared to no VT/VF were 5.59 and 2.34, respectively.

"In this study, occurrence of VT/VF before or after the end of cardiac catheterization in patients presenting for primary PCI was associated with increased 90-day mortality," the authors write.

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Cholesterol Level Linked to Death After Coronary Intervention

After percutaneous coronary intervention, very low high-density lipoprotein cholesterol linked to nearly double risk of death

10 april 2009-- Low levels of high-density lipoprotein (HDL) cholesterol were associated with higher one-year mortality in patients following percutaneous coronary intervention, according to research published in the April 1 issue of the American Journal of Cardiology.

Ziyad B. Ghazzal, M.D., of Emory University in Atlanta, and colleagues analyzed data from 4,088 patients who underwent percutaneous coronary intervention from 2001 to 2004. The researchers divided patients into approximate HDL quartiles: very low, less than 35 mg/dL; low, 35 to 40 mg/dL; medium, 41 to 47 mg/dL; and high, 48 to 120 mg/dL.

One-year mortality was nearly twice as high in those with the lowest HDL compared to the other groups (6.5 percent versus 3.5 percent), the investigators found. Revascularization was also higher in the lowest HDL group compared to the others (25.4 percent versus 21.3 percent). In multivariable analysis, very low HDL remained a predictor of one-year mortality (hazard ratio, 1.9), the researchers report.

"Patients with low levels of HDL cholesterol are at an increased risk of developing coronary artery disease. Epidemiologic studies have established an independent inverse association between HDL cholesterol levels and coronary artery disease event rates. For a 1-mg/dL increase in HDL cholesterol levels, coronary artery disease risk decreases by 2 percent to 3 percent. An association between HDL cholesterol and mortality has also been described," the authors write.

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Bleeding Linked to Cardiovascular Events After PCI

Death, heart attack and stroke more likely in patients with substantial periprocedural bleeding

07 april 2009-- Bleeding complications associated with percutaneous coronary intervention (PCI) may raise the risk of adverse outcomes in patients, according to research published in the April 1 issue of the American Journal of Cardiology.

Jasper Jan Brugts, M.D., of the Erasmus Medical Center in Rotterdam, the Netherlands, and colleagues analyzed data from nearly 7,000 patients who underwent PCI. The authors classified patients by their periprocedural bleeding status (none, mild, moderate and severe) and assessed the outcomes of all-cause mortality and a composite of death, myocardial infarction or stroke. Subjects were followed for a median of 210 days.

The researchers found that in multivariate analysis, moderate and severe bleeding was associated with a higher risk of the composite outcome (hazard ratios, 2.38 and 3.55, respectively). Severe bleeding was associated with a higher risk of all-cause mortality (hazard ratio, 20.86). The need for blood transfusion was also associated with the composite endpoint (hazard ratio, 2.61), the report indicates.

"Three pathophysiologic mechanisms might explain the association among PCI, bleeding and death. First, periprocedural bleeding complications may be related to systemic inflammatory processes that increase the risk of subsequent thrombosis. Second, periprocedural bleeding or bleeding soon after PCI might lead to early cessation of dual-anti-platelet therapy, which was associated with increased cardiovascular events. Third, periprocedural bleeding led to blood transfusions that might themselves lead to increased cardiovascular risk," the authors conclude.

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TCT: Bivalirudin (Angiomax) Effective in Primary PCI for STEMI

WASHINGTON, Oct. 24 -- Bivalirudin (Angiomax) as monotherapy saved lives and significantly reduced major bleeding at 30 days in patients with ST-elevation myocardial infarction undergoing primary stenting, investigators reported here.The direct thrombin inhibitor was compared with a standard anti-coagulation therapy of a glycoprotein IIb/IIIa inhibitor (abciximab) plus unfractionated heparin, Gregg W. Stone, M.D., of Columbia University, told a packed house at the Transcatheter Cardiovascular Therapeutics late-breaking clinical trials plenary today.
At 30 days in the HORIZONS AMI trial, the rate of net adverse clinical events was 12.1% in the control arm versus 9.2% in the bivalirudin monotherapy arm (P=0.006), Dr. Stone said. The cardiac mortality was 1.8% in the bivalirudin arm versus 2.9% in the abciximab plus heparin arm (P=0.035), and the major bleeding rate was 4.9% versus 8.3% in the control arm (P£0.0001).
Overall mortality was 2.1% in the bivalirudin group versus 3.1% in the control arm, but overall mortality eluded statistical significance (P=0.058).
During a press conference, Dr. Stone said there was "no question of non-inferiority here -- bivalirudin was clearly superior."
Marc Cohen, M.D., of Mount Sinai Medical School and chief of interventional cardiology at Newark Beth Israel Hospital, who was not involved in the HORIZONS trial, did not agree.
In an interview, he said the data suggest that bivalirudin may be a good option for some "low risk, uncomplicated STEMI patients," but there were some disturbing signals.
For example, "the stent thrombosis rate within 24 hours of procedure was 0.3% in the GP IIb/IIIa/heparin arm versus 1.3% in the bivalirudin arm and that was significant at P=0.0009," Dr. Cohen said.
Likewise the ischemic target vessel revascularization rate of 1.9% in the control arm versus 2.6% in the bivalirudin arm "while not a statistically significant difference, was headed in the wrong way," Dr. Cohen said.
But Dr. Cohen was in the minority as Dr. Stone's presentation was greeted with enthusiastic applause and the discussant, Michael Bertrand, M.D., of the University of Lille in Lambersart, France, emphasized the positive findings of the trial in his critique.
"And I think it was surprising to see a reduction in cardiac death in a trial with these small numbers," Dr. Bertrand said during a press conference. "That is important."
Christopher Cannon, M.D., of Brigham and Women's Hospital and Harvard Medical School, was similarly impressed. "It had less bleeding and interestingly this seemed to translate into fewer cardiac deaths," he said.
Because bleeding risk is a major concern during interventions "it seems that bivalirudin would be a good choice for patients where bleeding is a concern," Dr. Cannon said in an interview. Dr. Cannon was not involved in the study.
The trial recruited 3,602 patients with symptomatic STEMI who were randomized in less than 12 hours from symptom onset. All patients were started on dual antiplatelet therapy and randomized in the emergency department to either unfractionated heparin plus abciximab (ReoPro) or eptifibatide (Integrilin) plus unfractionated heparin (n=1,800) or bivalirudin.
The 30-day follow-up data were complete on 1,778 controls and 1,777 bivalirudin patients, but analysis was based on intention to treat.
The 30-day results, Dr. Stone emphasized, are just the first installment from the HORIZONS AMI story. These pharmacologic results represent "a strategy trial," he said. After angiography, patients were referred for coronary artery bypass surgery (2.2% in the control arm and 1.3% in the bivalirudin group), medical management (5.4% in the control group and 5.2% in the bivalirudin group) or percutaneous coronary intervention (92.2% of controls and 93.2% of bivalirudin patients).
Three thousand of the patients went on to stenting and were randomized to either bare-metal stents or paclitaxel-eluting (Taxus) stents. The results of that second phase are not yet known, Dr. Stone said.
The primary 30-day endpoint was net adverse clinical events and major bleeding, which was defined as intracranial bleeding, intraocular bleeding, retroperitoneal bleeding, access site bleeding requiring surgery, hematoma ≥ 5 cm, blood product transfusion, reoperation for bleeding, Hgb↓≥3 g/dL with an overt source, and Hgb↓≥ 4 g/dL without an overt source.
The HORIZONS AMI trial was funded by the Medicines Company and Boston Scientific via unrestricted educational grants to the Cardiovascular Research Foundation, which Dr. Stone said maintained complete control over the study design and data. Dr. Stone disclosed research support from The Medicines Company and Boston Scientific and honoraria from Pfizer. Dr. Cohen disclosed support from Sanofi-Aventis, Schering-Plough, Bristol-Myers Squibb, and "some funding from The Medicines Company". Dr. Cannon disclosed support from Merck, Schering-Plough, AstraZeneca, GlaxoSmithKline, and Bristol-Myers Squibb.Primary source: Transcatheter Cardiovascular TherapeuticsSource reference: Stone, GW et al "HORIZONS AMI A Prospective, Randomized Comparison of Bivalirudin vs. Heparin Plus Glycoprotein IIb/IIIa Inhibitors During Primary Angioplasty in Acute Myocardial Infarction 30 Day Results" Late Breaking Clinical Trials