Doses are shown as the proportion or percent of daily target dose - 50 - n293. Because dose-response studies have not been performed in survival trials following mi, there are no data to evaluate the efficacy of lower beta-blocker doses, but there are some data from heart failure trials. The purpose of this report is to determine whether the evidence-based quality assurance initiatives that have increased beta-blocker use at discharge have also impacted the issue of underdosing of beta-blockers, by evaluating beta blocker doses in patients enrolled in the the pace-mi trial is a randomized clinical trial evaluating whether pacemaker facilitated beta-blocker therapy after mi in patients who have bradycardia contraindications to beta-blockers improves survival.
Of the 1378 patients who were taking beta-blockers at 3-week follow-up, metoprolol accounted for 69. Although quality improvement initiatives have had enormous impact on the problem of beta-blocker underuse following mi, underdosing remains a significant problem. Multiple logistic regression was used to model predictors of no beta-blocker or very low beta-blocker dose at discharge and 3-week follow-up.
The odds ratio (or) and 95 confidence intervals (ci) are listed with the specific criterion indicating use of very low dose beta-blockers. At the end of three-week follow-up period, only 46 patients were taking 50 of the target dose shown to be beneficial in clinical trials. In the multivariable analysis, absence of hypertension, acute percutaneous coronary intervention, older age, and lack of ace-inhibitor therapy were consistent predictors of treatment with very low doses of beta-blockers.
Participating sites are listed in the all patients admitted with acute mi at participating sites were entered into the registry. Patient characteristics were compared using chi-square tests for categorical variables and analysis of variance for continuous variables. Clinical characteristics of the population, also stratified by beta-blocker dose at discharge (p-values indicate whether there are significant differences based on beta-blocker dose).
All data were collected at the site and de-identified patient information was entered in a web based electronic data capture system (medidata, new york, ny). These studies, predominantly reflecting practice patterns in the 1990s, showed that the vast majority of patients discharged on beta-blockers did not achieve the target doses demonstrated to be effective in the randomized trials. It is also interesting to examine the dose distribution of metoprolol in merit-hf at 3 month follow-up (including 90 of patients enrolled, over half of whom had nyha functional class iii heart failure).
These data demonstrate that despite the widespread success of current quality improvement initiatives, underdosing of beta-blocker therapy remains a significant clinical issue. It should be noted that this study enrolled only patients whose left ventricular ejection fraction was 40. This represents an important opportunity in quality improvement for the care of patients who have suffered a mi. At study end, 57 were receiving the full-protocol propranolol dose (85 still on a beta-blocker). Interestingly, the commit trial , in which rapid titration to target doses was performed, demonstrated no survival benefit.
Thus, randomized clinical trials support the ability of achieving target doses in the majority of patients, even the elderly and patients with heart failure, with the vast majority able to take 50 of the target dose. It is therefore important to explore both the clinical implications of underdosing, potential reasons for not achieving higher doses, and further steps to address this issue. This represents an important opportunity in quality improvement for the care of patients who have suffered a mi. Based on the doses administered, a proportion of target dose was calculated (dose administeredtarget dose). Furthermore, 54 of patients were still being treated with 25 of the dose shown to be effective in clinical trials.
The graph shows the distribution of beta-blocker dosing (shown as percent of daily target dose see legend) at 3 weeks stratified by whether the dose was reduced (n171), remained the same (n1095), or increased (n167) since hospital discharge. Although quality improvement initiatives have had enormous impact on the problem of beta-blocker underuse following mi, underdosing remains a significant problem. This contrasts with the dosing used in randomized clinical trials of beta-blockers which have shown a very high success rate of achieving target dose these trials and the dosing used serve as the basis for the survival benefit of post-mi beta-blocker therapy. Basic demographic, historical, and hospitalization information, as well as information regarding the index mi, was collected. While guidelines and performance measures for the care of post-mi patients clearly indicate that virtually all such patients should be treated with beta-blocker therapy, the guidelines are silent on dosing.
Patients on target dose had a two-year mortality of approximately 10, while those at below target dose had a two-year mortality of approximately 20. Prior beta-blocker use was noted in 32 of patients and was associated with a higher discharge dose (48. Patient characteristics were compared using chi-square tests for categorical variables and analysis of variance for continuous variables. Interestingly, the commit trial , in which rapid titration to target doses was performed, demonstrated no survival benefit. A recent european survey demonstrated that 80 of patients with acute mi were treated with beta-blockers. Peak total cpk and troponin values were recorded, as available (5 sites used troponin t) because of the multiple laboratories and the wide range of reported upper limits of normal among the sites, only a median value is provided and this was not used for further analysis. In june2008, the steering committee and dsmb reviewed the progress of the study as well as registry data. . It is also interesting to examine the dose distribution of metoprolol in merit-hf at 3 month follow-up (including 90 of patients enrolled, over half of whom had nyha functional class iii heart failure). Data are reported for metoprolol, the most commonly prescribed beta-blocker, separately and for all beta-blockers for which target dose could be identified.In order to enhance beta-blocker use post-MI, this was selected to be a key ... discharge summary, cardiac catheterization report, and medication sheets. .... Each bar is subdivided to indicate metoprolol dosing and dosing of other beta- blockers. .... taking 25mg/day (50% of target) and 7% taking 12.5mg/day (25% of target).