Tuesday, April 21, 2015

Detrimental effect of hyperoxia post-arrest

From a recent systematic review and meta-analysis:

Studies have shown the detrimental effect of hyperoxia in animals with return of spontaneous circulation (ROSC) after cardiac arrest. To maximize the value of existing clinical studies, we performed the systemic review and meta-analysis of human observational studies to examine the effect of hyperoxia on outcomes of post-ROSC patients...

Results
Fourteen studies were identified from 2982 references. Odds ratio (OR) was used as effect estimate. OR was reconstructed if not provided in original articles. Hyperoxia was defined as a PaO2 greater than 300 mmHg. Meta-analysis indicated that hyperoxia appeared to be correlated with increased in-hospital mortality (OR, 1.40; 95% CI, 1.02–1.93; I2, 69.27%; 8 studies) but not worsened neurological outcome (OR, 1.62; 95% CI, 0.87–3.02; I2, 55.61%; 2 studies). However, the results were inconsistent in subgroup and sensitivity analyses.

Conclusions
Hyperoxia appears to be correlated with increased in-hospital mortality of post-ROSC patients.

Monday, April 20, 2015

Emerging evidence for mineralocorticoid receptor antagonists in heart failure with preserved ejection fraction

Form a review:

Recent findings: Three randomized trials were reviewed: the Effect of spironolactone on diastolic function and exercise capacity in patients with heart failure with preserved ejection fraction: the Aldo-DHF randomized controlled trial; the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial; and its echocardiography substudy. The Aldo-DHF trial showed improvements in echocardiographic measures of diastolic function. In the Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist trial, hospitalization for heart failure was significantly reduced with MRA therapy with no difference in the primary outcome of cardiovascular death or hospitalization. In patients with high risk, however, there may be a reduction in cardiovascular mortality. We will also briefly discuss finerenone, a new generation MRA associated with a lower incidence of hyperkalemia.

Summary: New evidence shows that MRA therapy decreases left ventricular mass and left atrial size, reduces hospitalization, and may reduce cardiovascular mortality in patients with high risk.

Sunday, April 19, 2015

Which newly diagnosed heart failure patients should be evaluated for ischemia and how?

From the 2013 ACCF/AHA guidelines (executive summary here):

No class I recommendations.

Assuming the patient is a potential revascularization candidate---

If ischemia “may be contributing” to heart failure: coronary angiography reasonable (class IIa).

Known CAD but no angina: non invasive imaging reasonable (class IIa).

Other indications for imaging may be present.

Saturday, April 18, 2015

Atrial fibrillation guidelines 2014


These are the latest from the American Heart Association, the American College of Cardiology and the Heart Rhythm Society.

Colon cleanse for hepatic encephalopathy?

From JAMA Internal Medicine:

We hypothesized that rapid catharsis of the gut using PEG may resolve HE more effectively than lactulose...

Design, Setting, and Participants The HELP (Hepatic Encephalopathy: Lactulose vs Polyethylene Glycol 3350-Electrolyte Solution) study is a randomized clinical trial in an academic tertiary hospital of 50 patients with cirrhosis (of 186 screened) admitted for HE.

Interventions Participants were block randomized to receive treatment with PEG, 4-L dose (n = 25), or standard-of-care lactulose (n = 25) during hospitalization.

Main Outcomes and Measures The primary end point was an improvement of 1 or more in HE grade at 24 hours, determined using the hepatic encephalopathy scoring algorithm (HESA), ranging from 0 (normal clinical and neuropsychological assessments) to 4 (coma). Secondary outcomes included time to HE resolution and overall length of stay.

Results A total of 25 patients were randomized to each treatment arm. Baseline clinical features at admission were similar in the groups. Thirteen of 25 patients in the standard therapy arm (52%) had an improvement of 1 or more in HESA score, thus meeting the primary outcome measure, compared with 21 of 23 evaluated patients receiving PEG (91%) (P less than .01); 1 patient was discharged before final analysis and 1 refused participation. The mean (SD) HESA score at 24 hours for patients receiving standard therapy changed from 2.3 (0.9) to 1.6 (0.9) compared with a change from 2.3 (0.9) to 0.9 (1.0) for the PEG-treated groups (P = .002). The median time for HE resolution was 2 days for standard therapy and 1 day for PEG (P = .01). Adverse events were uncommon, and none was definitely study related.

Conclusions and Relevance PEG led to more rapid HE resolution than standard therapy, suggesting that PEG may be superior to standard lactulose therapy in patients with cirrhosis hospitalized for acute HE.

Friday, April 17, 2015

Anticoagulation decisions for patients with atrial fibrillation


This review recently appeared in the Cleveland Clinic Journal of Medicine. It centers around the updated guidelines promulgated last year by the American Heart Association, American College of Cardiology, and Heart Rhythm Society.

Although it's pretty much the usual rundown, a few points of particular interest are noteworthy:


The new guidelines favor risk assessment using the CHA2DS2-VASc score instead of CHADS2.


HAS-BLED should not be used to exclude patients from anticoagulation therapy.

This is because in all patients except for those at the very lowest risk for thromboembolism the risk of stroke exceeds the risk of intracranial bleeding. Low risk patients will be excluded by the CHA2DS2-VASc score. That being said, HAS-BLED can be useful in identifying patients in need of closer monitoring.


Diminishing importance of aspirin in the guidelines

From the review:

Aspirin has been compared with placebo in seven randomized controlled trials. Only the original SPAF study, in which aspirin 325 mg/day was used, found that it was beneficial. This result alone accounted for the 19% reduction in relative risk (95% CI 1%–35%, P less than .05) in a meta-analysis performed by Hart et al.29 Even when combined with clopidogrel 75 mg/day, aspirin 75 to 100 mg/day is still inferior to warfarin.5 While dual antiplatelet therapy resulted in a 28% relative reduction in thromboembolism (95% CI 17%–38%, P less than .01) compared with aspirin alone, major bleeding significantly increased by 57% (95% CI 29%–92%, P less than .01)...

The 2014 guidelines downgraded the recommendation for aspirin therapy. For patients at low risk and for some at intermediate risk, it is permissible to forgo therapy altogether, including aspirin.1


Patients with hypertrophic cardiomyopathy warrant special consideration.

Patients with AF who also have HCM should receive systemic anticoagulation regardless of the CHA2DS2-VASc score, as a class I recommendation in the new guidelines. This can be done with either TSOACs or warfarin.


Heart block complicating acute MI: does it impact long term outcomes in the PCI era?

From a nationwide database:

This study was conducted to investigate the prognostic value of heart block among patients with acute myocardial infarction (AMI) treated with drug-eluting stents. A total of 13,862 patients with AMI, registered in the nation-wide AMI database from January 2005 to June 2013, were analyzed. Second- (Mobitz type I or II) and third-degree atrioventricular block were considered as heart block in this study. Thirty-day major adverse cardiac events (MACE) including all causes of death, recurrent myocardial infarction, and revascularization were evaluated. Percutaneous coronary intervention with implantation of drug-eluting stent was performed in 89.8% of the patients. Heart block occurred in 378 patients (2.7%). Thirty-day MACE occurred in 1,144 patients (8.2%). Patients with heart block showed worse clinical parameters at initial admission, and the presence of heart block was associated with 30-day MACE in univariate analyses. However, the prognostic impact of heart block was not significant after adjustment of potential confounders (p = 0.489). Among patients with heart block, patients with a culprit in the left anterior descending (LAD) coronary artery had worse clinical outcomes than those of patients with a culprit in the left circumflex or right coronary artery. LAD culprit was a significant risk factor for 30-day MACE even after controlling for confounders (odds ratio 5.28, 95% confidence interval 1.22 to 22.81, p = 0.026). In conclusion, despite differences in clinical parameters at the initial admission, heart block was not an independent risk factor for 30-day MACE in adjusted analyses. However, a LAD culprit was an independent risk factor for 30-day MACE among patients with heart block.

Thursday, April 16, 2015

Pulmonary embolism overview


Great post at S.O.A.P. along with links to other resources in the FOAM community.

Using hemoglobin and hematocrit to guide diuresis in heart failure

From a review:

Hemoconcentration was consistently associated with markers of aggressive fluid removal, including higher diuretic dosing and reduced body weight, but increased risk of in-hospital worsening renal function. Despite this, hemoconcentration was associated with improved short-term mortality and rehospitalization. Hemoconcentration is a practical, readily available, noninvasive, economically feasible strategy to help guide diuresis and monitor congestion relief in patients hospitalized for worsening heart failure. Clinicians should strongly consider using changes in hemoglobin and hematocrit as an adjunct..

Wednesday, April 15, 2015

Therapeutic hypothermia (targeted temperature management) post cardiac arrest implemented as a systems improvement at Kaiser Permanente


Here are the surprising findings of the retrospective cohort study carried out at 21 centers in their integrated delivery system:

Methods

Retrospective cohort study of patients with OHCA admitted to 21 medical centers between January 2007 and December 2012. A standardized TTM protocol and educational program were introduced throughout the system in early 2009. Comatose patients eligible for treatment with TTM were included. Adjusted odds of good neurologic outcome at hospital discharge and survival to hospital discharge were assessed using multivariate logistic regression.

Results

A total of 1119 patients were admitted post-OHCA with coma, 59.1% (661 of 1119) of which were eligible for TTM. The percentage of patients treated with TTM markedly increased during the study period: 10.5% in the years preceding (2007–2008) vs. 85.1% in the years following (2011–2012) implementation of the practice improvement initiative. However, unadjusted in-hospital survival (37.3% vs. 39.0%, p = 0.77) and good neurologic outcome at hospital discharge (26.3% vs. 26.6%, p = 1.0) did not change. The adjusted odds of survival to hospital discharge (AOR 1.0, 95% CI 0.85–1.17) or a good neurologic outcome (AOR 0.94, 95% CI 0.79–1.11) were likewise non-significant.

Interpretation

Despite a marked increase in TTM rates across hospitals in an integrated delivery system, there was no appreciable change in the crude or adjusted odds of in-hospital survival or good neurologic outcomes at hospital discharge among eligible post-arrest patients.

The authors were unable to explain the negative findings, which go against the strength of prior high level evidence, and correctly point out that this study should not be taken as evidence against the use of therapeutic hypothermia.


Eosinophilic esophagitis review

This emerging disease first described in 1993 is the topic of a review in CCJM.