title: Carvedilol versus metoprolol in patients undergoing direct percutaneous coronary interventions for myocardial infarction: effects on QT dynamicity.
abstract: Beta-adrenergic blockers exert significant antiarrhythmic activity during ischemia and reperfusion. To further explore the beneficial effects conferred by alpha-1-adrenoceptor blockade on ventricular repolarization dynamicity in the acute phase of myocardial infarction (AMI), we compared carvedilol with metoprolol in the setting of primary percutaneous coronary intervention (PCI). In a prospective study, 100 consecutive patients undergoing primary PCI for AMI were randomized to metoprolol 200 mg/day versus carvedilol 25 mg/day. The first oral dose of study drug was administered and a 24-hour ambulatory electrocardiogram recorded upon hospital admission. Slopes of the linear QT/RR regression were determined before and after reperfusion. A total of 38 recordings of patients treated with metoprolol and 34 recordings of patients with carvedilol were eligible for analysis of QT/RR slopes. The two study groups were similar with respect to age, gender, TIMI perfusion grades, ventricular function, duration of ischemia, and site and size of infarction. Mean RR- and QT-intervals were similar to the metoprolol and carvedilol groups, before and after PCI. Likewise, there was no significant difference in QT/RR slopes between the metoprolol and carvedilol groups before PCI. In contrast, after PCI, there was a trend toward lower QT/RR slopes in the metoprolol group (from 0.18 +/- 0.07 to 0.17 +/- 0.08), and a significant decrease in QT/RR slopes in the carvedilol group (from 0.17 +/- 0.07 to 0.14 +/- 0.09). In patients undergoing successful direct PCI for AMI, treatment with carvedilol, in contrast to metoprolol, was associated with a significant decrease in QT-RR slopes, suggesting greater cardiac electrical stability.
authors.affiliation: Medizinische Kinik II, Universität zu Lübeck, Lübeck, Germany. bonnemei@medinf.mu-luebeck.de
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bonnemeier
authors.forename: Jasmin
authors.initials: J
authors.lastname: Ortak
authors.forename: Ralph
authors.initials: R
authors.lastname: Tölg
authors.forename: Maren
authors.initials: M
authors.lastname: Witt
authors.forename: Jörg
authors.initials: J
authors.lastname: Schmidt
authors.forename: Uwe K H
authors.initials: UK
authors.lastname: Wiegand
authors.forename: Frank
authors.initials: F
authors.lastname: Bode
authors.forename: Heribert
authors.initials: H
authors.lastname: Schunkert
authors.forename: Gert
authors.initials: G
authors.lastname: Richardt
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D015906:Angioplasty, Balloon, Coronary; D002227:Carbazoles / Q000627:therapeutic use*; D000077261:Carvedilol; D003131:Combined Modality Therapy; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology* / Q000628:therapy*; D011412:Propanolamines / Q000627:therapeutic use*; D011446:Prospective Studies
chemical_list: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D008790:Metoprolol