Cardiac

ICU Renal Replacement and Long term Morbidity

Renal replacement therapy in ICU may predict increased cardiovascular morbidity in the long term compared to those who did not receive it. This Korean study showed a higher major cardiovascular event rate, mortality and rate of end stage renal disease. Where renal replacement has been used in ICU survivors, increased vigilance is needed long term as well as management of risk factors.

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Erythropoietin (EPO) in Cardiac Surgery

A retrospective study compares outcomes in cardiac surgery in those who declined transfusion and received EPO  with those who did not receive EPO or transfusion. Allowing for the limitations of retrospective design, they found no difference in mortality, MI, stroke, thromboembolism, kidney injury, extubation time, ICU or hospital length of stay. The results are encouraging for those who decline transfusion such as Jehovah Witnesses but further larger prospective trials are needed. EPO remains off-label for this use.

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Epinephrine for Out of Hospital Cardiac Arrest

Despite its central role in ACLS, the use of Epinephrine and outcome has been controversial. A major study finds “the use of epinephrine resulted in a significantly higher rate of 30-day survival than the use of placebo, but there was no significant between-group difference in the rate of a favorable neurologic outcome because more survivors had severe neurologic impairment in the epinephrine group”.

Postulated mechanisms include impairment of microvascular cerebral blood flow or possible reperfusion injury. So Epinephrine may improve survival but at a cost. The most important message to reiterate is how vital rapid CPR and defibrillation are.

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Albumin and Cardiac Surgery Mortality

An observational study of on-pump cardiac surgery links the use of 5% Albumin to lower in-hospital mortality and lower 30 day readmission when Albumin + crystalloid was used compared to only crystalloid. Composite morbidity and acute kidney injury did not differ. Randomized studies would be needed to confirm these findings but Albumin seems to hold more promise than the now discredited colloids like hydroxyethyl starch.

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Cardiac Risk Prediction

A retrospective observational study compared well established cardiac risk prediction models: (i)the Revised Cardiac Risk Index, (ii)American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator, and (iii)the Myocardial Infarction or Cardiac Arrest calculator.

While agreement was better between the latter two (ACS NSQIP and MICA), there was 30% discordance between assigning high or low risk compared to the RCRI.

The NSQIP certainly seems more modern and comprehensive than the RCRI but the divergence in risk assessment certainly needs to be borne in mind.

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Assessment of functional capacity before major non-cardiac surgery

Functional capacity is frequently subjectively assessed but this prospective cohort study recommends against it in favour of more objective measures. They compared it with alternative markers of fitness (cardiopulmonary exercise testing [CPET], scores on the Duke Activity Status Index [DASI] questionnaire, and serum N-terminal pro-B-type natriuretic peptide [NT pro-BNP] concentrations) for predicting death or complication. Only DASI scores were associated with predicting the primary outcome of death or myocardial infarction within 30 days.

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Bicuspid Aortic Valve and Mitral Valve Prolapse

In recent years the guidelines for bacterial endocarditis antibiotic prophylaxis have been drastically curtailed. This Spanish study calls for reconsideration, in that patients with bicuspid aortic valves and mitral valve prolapse had viridans endocarditis with a similar profile to other high risk endocarditis cases.

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Hypertension and Intra-operative Hemodynamics

An observational study fails to link pre-op hypertension to adverse intra-op hemodynamics like hypotension and tachycardia, factors known to increase major adverse cardiovascular morbidity and mortality. It supports AAGBI guidelines and others to continue with elective surgery in patients with blood pressure less than 180/110

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Dabigatran for Myocardial Injury in Non-Cardiac Surgery

In the MANAGE trial, the use of 110mg bid Dabigatran reduced the incidence of major vascular complications (without an increase in bleeding) after myocardial injury within 35 days of non-cardiac surgery. The difference wasn’t huge and the trial stopped early, and discontinuance rates of Dabigatran were high. The myocardial injury consisted of isolated Troponin elevations in 80% of cases. Low enrolment and change of primary endpoint were further limitations. So the question of monitoring Troponin levels continues as interventions are needed and this study is not overwhelmingly convincing in lowering death from MI, Stroke and other vascular complications.

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