Initiation of ß-blocker therapy and depression after acute myocardial infarction.

INTRODUCTION: Although ß-blockers reduce mortality after acute myocardial infarction (AMI), early reports linking ß-blocker use with subsequent depression have potentially limited their use in vulnerable patients. We sought to provide empirical evidence to support or refute this concern by examining the association between ß-blocker initiation and change in depressive symptoms in AMI patients. METHODS: Using data from 2 US multicenter, prospective registries of AMI patients, we examined 1-, 6-, and 12-month changes in depressive symptoms after the index hospitalization among patients who were ß-blocker-naïve on admission. Depressive symptoms were assessed using the validated 8-item Patient Health Questionnaire (PHQ-8), which rates depressive symptoms from 0 to 24, with higher scores indicating more depressive symptoms. A propensity-matched repeated-measures linear regression model was used to compare change in depressive symptoms among patients who were and were not initiated on a ß-blocker after AMI. RESULTS: Of 3,470 AMI patients who were ß-blocker-naïve on admission, 3,190 (91.9%) were initiated on a ß-blocker and 280 (8.1%) were not. Baseline PHQ-8 scores were higher in patients not initiated on a ß-blocker (mean 5.78 ± 5.45 vs 4.88 ± 5.11, P = .005). PHQ-8 scores were progressively lower at 1, 6, and 12 months in both the ß-blocker (mean decrease at 12 months 1.16, P < .0001) and no-ß-blocker groups (mean decrease 1.71, P < .0001). After propensity matching 201 untreated patients with 567 treated patients, initiation of ß-blocker therapy was not associated with a difference in mean change in PHQ-8 scores at 1, 6, or 12 months after AMI (absolute mean difference with ß-blocker initiation at 12 months of 0.08, 95% CI -0.81 to 0.96, P = .86). CONCLUSIONS: Initiation of ß-blocker therapy after AMI was not associated with an increase in depressive symptoms. Restricting ß-blocker use because of concerns about depression appears unwarranted and may lead to undertreatment of AMI patients.

High-concentration versus titrated oxygen therapy in ST-elevation myocardial infarction: a pilot randomized controlled trial.

BACKGROUND: The optimal approach to oxygen therapy in ST-elevation myocardial infarction (STEMI) is uncertain. METHODS: A randomized controlled trial was undertaken in which 136 patients presenting with their first STEMI uncomplicated by cardiogenic shock or marked hypoxia were randomized to receive high-concentration (6 L/min via medium concentration mask) or titrated oxygen (to achieve oxygen saturation 93%-96%) for 6 hours after presentation. The main outcome variables were 30-day mortality and infarct size assessed by troponin T level at 72 hours. Secondary outcomes included a meta-analysis of mortality data from this study and previous randomized controlled trials, and infarct size was assessed by magnetic resonance imaging at 4 to 6 weeks. RESULTS: There were 1 of 68 and 2 of 68 deaths in the high-concentration and titrated oxygen groups, respectively; a meta-analysis including these data with those from the 2 previous studies showed an odds ratio for mortality of high-concentration oxygen compared with room air or titrated oxygen of 2.2 (95% CI 0.8-6.0). There was no significant difference between high-concentration versus titrated oxygen in troponin T (ratio of mean levels 0.74, 95% CI 0.50-1.1, P = .14), infarct mass (mean difference -0.8 g, 95% CI -7.6 to 6.1, P = .82), or percent infarct mass (mean difference -0.6%, 95% CI -5.6 to 4.5, P = .83). CONCLUSION: This study found no evidence of benefit or harm from high-concentration compared with titrated oxygen in initially uncomplicated STEMI. However, our estimates have wide CIs, and as a result, large randomized controlled trials are required to resolve the clinical uncertainty.

A randomised controlled trial of the effect of high concentration oxygen on myocardial ischaemia during exercise.

BACKGROUND: International guidelines recommend the use of oxygen for angina, based on Level C evidence. We aimed to determine whether high concentration oxygen influences the time to exercise-induced ischaemia or angina in patients with stable ischaemic heart disease (IHD). METHODS: 22 subjects with IHD and a positive exercise treadmill test (ETT) awaiting coronary angiography were randomised to two further ETTs according to a double-blind, crossover study design, during which they breathed oxygen or air at 15 L/min via a non-rebreather mask. Subjects in whom significant coronary artery disease was not subsequently confirmed by coronary angiography were excluded from analysis. The primary outcome was time to exercise-induced myocardial ischaemia, defined as ≥ 1 mm ST depression on contiguous electrocardiographic (ECG) leads. The secondary outcome was time to onset of angina. RESULTS: Exercise-induced myocardial ischaemia occurred in 17 of the 19 subjects with coronary artery disease, with the remaining two stopping due to shortness of breath. The mean (SD) time to inducible ischaemia was 35 (47) s longer (95% CI 11 to 59, P=0.007) with oxygen compared to air. Exercise-induced angina occurred in 9 subjects and started a mean 19 (32) s later (95% CI -6 to 43, P=0.12) with oxygen compared to air. All subjects who developed myocardial ischaemia or angina did so during both of the study ETTs. CONCLUSION: High concentration oxygen increases the time to onset of exercise-induced myocardial ischaemia in patients with stable IHD.

Same-day discharge is feasible and safe in the majority of elderly patients undergoing elective percutaneous coronary intervention.

BACKGROUND: Same-day discharge after elective percutaneous coronary intervention (PCI) is safe in the majority of patients. However, the elderly have more comorbidities and less favorable coronary and peripheral arterial anatomy, which may preclude safe same-day discharge after PCI. We assessed the feasibility and safety of same-day discharge in an elderly cohort of patients. METHODS: A total of 1,580 consecutive patients undergoing elective PCI in a single center between January 2001 and January 2009 were included in the study. We compared the outcomes of elderly patients aged 75 or older to control patients under the age of 75 years. Patients were examined 6 hours post procedure and discharged if there were no complications. RESULTS: Of the 1,580 study patients 212 (13.4%) were elderly and 1,365 (86.6%) were younger controls. The elderly were more likely to be female, hypertensive and to have had previous coronary artery bypass graft (CABG) surgery and less likely to be smokers or to have hyperlipidemia (all p < 0.05). The number of lesions treated and their complexity were similar in both groups. Procedural success, in-hospital major adverse cardiac events (MACE) and the rates of same-day discharge were also similar in both groups. Same-day discharge was achieved in the majority (84%) of the elderly. There were no deaths within 24 hours of discharge. Readmission within 24 hours of discharge was rare (< 0.7%) in both groups. The 30-day MACE rate was low in both the elderly (3.3%) and control groups (3.6%; p = 1.0). CONCLUSIONS: Same-day discharge is safe and feasible in the majority of elderly patients following elective PCI.

Paramedic-administered prehospital thrombolysis is safe and reduces time to treatment.

INTRODUCTION: The Kapiti Coast region is remote from Wellington Hospital with an ambulance transport time of 1 hour. To reduce delays in the treatment of myocardial infarction (MI), a prehospital thrombolysis (PHT) programme was initiated in 2003. METHODS: This study evaluated outcomes of the Kapiti PHT programme between 2003 and 2007. Paramedics attending patients with suspected MI-transmitted electrocardiograms to our Coronary Care Unit where a physician made the decision whether or not to thrombolyse. Thrombolysis was then administered by a paramedic. Patients from the Kapiti region treated with in-hospital thrombolysis (IHT) between 1999 and 2003 formed the control group. RESULTS: A total of 50 Kapiti patients received PHT. The group receiving IHT were older than those receiving PHT but other baseline characteristics were similar. No patients without MI or with a contraindication received PHT. In the PHT group there was one minor bleed but no major bleeding, stroke or death occurred during transport to hospital. The median scene to thrombolytic time for PHT was 89 minutes faster (44 minutes versus 133, P<0.0001) than in patients transferred for IHT. The median scene to thrombolytic time for PHT was similar to the door to thrombolytic time for IHT (P=0.13). In-hospital mortality in the PHT group (8.0%) was similar to the IHT group (6.0%, P=1.0) but heart failure was reduced (10% vs. 26%, P=0.04) CONCLUSIONS: Prehospital thrombolysis administered by paramedics is safe and reduces the time to treatment and was associated with a reduction in heart failure.