Under utilization of implantable cardioverter-defibrillators post MI

Many health policy experts claim that reduction of variation in treatments by adherence to evidence based medicine would curb costs. This claim cannot be substantiated. It is equally possible that uniform adherence to EBM would increase costs, based on known under utilization of treatments. This is illustrated by a recent JAMA report showing marked under utilization of a very expensive treatment:

Objective To examine ICD implantation rates and associated mortality among older MI patients with low ejection fraction (EF).

Design, Setting, and Participants Retrospective observational study of Medicare beneficiaries with an EF of 35% or less after MI, treated at 441 US hospitals between 2007 and 2010, excluding patients with prior ICD implantation. Follow-up data were available through December 2010.

Exposures ICD implantation within 1 year of MI vs no ICD implantation within 1 year of MI.

Main Outcomes and Measures Patient characteristics associated with receiving an ICD within 1 year after discharge and 2-year mortality associated with ICD implantation.

Results Among 10 318 MI patients with EF of 35% or lower, the cumulative 1-year ICD implantation rate was 8.1% (95% CI, 7.6%-8.7%; n = 785). Patients with ICD implantation were more likely to have prior coronary artery bypass graft procedures (31% vs 20%; adjusted hazard ratio [HR], 1.49; 95% CI, 1.26-1.78), higher peak troponin levels (median, 85 vs 51 times the upper limit of normal; adjusted HR, 1.02 per 10-fold increase; 95% CI, 1.01-1.03), in-hospital cardiogenic shock (13% vs 8%; adjusted HR, 1.57; 95% CI, 1.25-1.97), and cardiology follow-up within 2 weeks after discharge (30% vs 20%; adjusted HR, 1.64; 95% CI, 1.37-1.95) relative to patients who did not receive an ICD within 1 year. Implantation of ICD was associated with lower 2-year mortality (15.3 events per 100 patient-years [128 deaths in 838 patient-years] vs 26.4 events per 100 patient-years [3033 deaths in 11 479 patient-years]; adjusted HR, 0.64; 95% CI, 0.53-0.78).

Conclusions and Relevance In this large registry study of older patients who experienced MI from 2007-2010, fewer than 1 in 10 eligible patients with low EF received an ICD within 1 year after MI, although ICD implantation was associated with lower risk-adjusted mortality at 2 years. Additional research is needed to determine evidence-based approaches to increase ICD implantation among eligible patients.

Systematic review of atrial fibrillation treatment

From JAMA. Nothing new here, and the review ignores recent research on obesity reduction as a treatment for atrial fibrillation.

Managing volume overload in decompensated heart failure

Key points from a review in mayo Clinic Proceedings:

Although larger trials are needed, small studies suggest the superiority of torsemide compared with other available loop diuretics.

Routine continuous intravenous infusion of loop diuretics offers no added benefits in removing fluid compared with intravenous bolus administration.

Nesiritide and dopamine have limited, if any, roles in managing volume overload in patients with acute decompensated heart failure.

Vasopressin antagonists may help decrease volume overload in patients with acute decompensated heart failure and hyponatremia.

Ultrafiltration can remove fluid in diuretic-refractory patients, but clinical studies show no benefits compared with more intensive, optimal diuretic therapy regimens.

Small observational and clinical studies have not shown a benefit in restricting sodium intake in patients with heart failure; further studies are required before a definitive conclusion can be reached.

Implantable hemodynamic monitoring devices have a promising future, and their role in managing heart failure will continue to evolve in the next 5 to 10 years.

Acute chest syndrome

From the Mayo Clinic EMBlog.

Does accreditation really improve hospital care?

This systematic review found insufficient evidence.

Accidental hypothermia

Here's a summary post from the Mayo EMBlog.

Pseudonormalization of the electrocardiogram during chest pain

A manifestation of Wellens syndrome.

Measurement of ventricular repolarization dispersion in chest pain

Although the authors of this paper, for purposes of discussion, use the generally accepted term “NSTEMI” in reference to acute coronary syndrome with subtle or non diagnostic ECG patterns, their findings suggest that the term is simplistic and of limited clinical usefulness.  Utilizing a specialized electrocardiographic technique to measure ventricular repolarization dispersion in  patients presenting with chest  pain they found:

Methods and Results We continuously recorded 12‐lead Holter ECGs from chest pain patients upon their arrival to the ED. VRD was quantified using principal component analysis of the 12‐lead ECG to compute a T‐wave complexity ratio (ie, ratio of second to first eigenvectors of repolarization). Clinical outcomes were obtained from hospital records. The sample was composed mainly of older males (n=369; ages 63±12 years; 63% males), and 92 (25%) had NSTEMI and 26 (7%) had MACEs. Baseline T‐wave complexity ratio modestly correlated with peak troponin levels (r=0.41; P less than 0.001) and was a good classifier of NSTEMI events (area under the curve=0.70). An increased T‐wave complexity ratio on the presenting ECG was strongly associated with NSTEMI (odds ratio [OR]=3.8 [2.1 to 5.8]) and in‐hospital MACE (OR=8.2 [3.1 to 21.5]).

Conclusions A simple measure of global VRD on the presenting 12‐lead ECG correlates with ischemic myocardial injury and can discriminate NSTEMI cases very early during evaluation. Prospective studies should validate these findings and test whether VRD can guide therapy.

More from the discussion section of the paper:

As such, our data suggest that a simple measure of T‐wave complexity is more sensitive for (1) detecting ischemic myocardial necrosis associated with NSTEMI and (2) quantifying the severity of ischemic burden to identify high‐risk NSTEMI patients who would benefit from early revascularization.

This paper convinces me more than ever that the STEMI/NSTEMI terminology needs to be abandoned.  If there is a meaningful binary distinction in ACS it would be between coronary occlusion and plaque instability without occlusion.   But the current STEMI/NSTEM designation is, according to increasing evidence and for multiple reasons, a poor surrogate tor presence of absence of occlusion.  Moreover, according to the data presented here, the decision for early cardiac catheterization ought to be based on assessment along a continuum of risk rather than a binary distinction.

Uric acid level as a marker for renal hemodynamics

Free full text review here concludes:

The results of many clinical and experimental studies clearly demonstrate that an increasing serum uric acid level may be a useful biomarker of hypertension and its consequently deranged renal hemodynamics. It is also evident that chronic hyperuricemia may adversely affect cardiovascular and renal structure and function and, therefore, may be a contributory event in the pathogenesis of cardiovascular and renal disorders. Thus, at present, there is no clear or convincing evidence that hyperuricemia is a causative factor in hypertensive disease or that lowering the uric acid concentration may reduce arterial pressure. Therefore, conventional pharmacotherapy, without uricosuric agents, is recommended in the treatment of hypertensive cardiovascular disease unless there is concern about tissue deposition of urate. One exception may be the population of obese hypertensive adolescents in whom reduction of hyperuricemia has been shown to result in a decreased arterial pressure.

Under diuresis of patients hospitalized with heart failure

---was associated with higher mortality and readmission rates in this study. A simple score based on orthopnea and pedal edema proved useful.

What is the best way to evaluate thrombocytopenia in the ICU?

Should we use a systematic approach to evaluate it as fully as possible? Traditionally we're more selective. We formulate an overall clinical impression, then specifically assess for things that are really horrible and require specific action (TTP, HIT).

A small before and after study compared the traditional selective approach with one in which all patients were evaluated as fully as possible:

Methods

Before-and-after study of all patients with thrombocytopenia was used. ‘Before’ group had no intervention. New standard operating procedures for thrombocytopenia management were introduced. In the ‘After’ group, bone marrow aspiration; determination of fibrinogen dosage, prothrombin time, factor V, D-dimers; assay of fibrin monomers, ferritin, triglycerides, lactic acid dehydrogenase, aspartate transaminase, alanine aminotransferase, vitamin B12, folates, reticulocytes, haptoglobin, and bilirubin were performed.

Results

In the Before group (n = 20), the mechanism (central, peripheral, or mixed) was identified in 10 % versus 83% in After group (n = 23) (p less than 0.001) (48% peripheral, 35% mixed). Before intervention, greater than or equal to 1 etiology was identified in 15% versus 95.7% in the After group (p less than  0.001).

Conclusions

Systematic and extensive investigation using routine tests highlights the mechanisms and etiology of thrombocytopenia in most cases.

More patients in the traditional group had normalization of platelet counts than did those who were fully evaluated. Evaluation in the traditional group did not drive any treatment. In the fully evaluated group two patients were given folic acid based on the evaluation and one received corticosteroids and IVIG after a bone marrow finding of hemophagocytosis.

Beta agonist induced stress cardiomyopathy occurring during asthma treatment

Here is a case report and brief review.

What is the evidence for treatment of asymptomatic left ventricular dysfunction?

This is now known as stage B heart failure.

Skin mottling over the knee

Commonly seen. Among septic shock patients, robustly associated with mortality.

Interatrial block

Reported here are two cases in which the block was intermittent (second degree) and seen during hemodialysis.

Scrub typhus

Free full text review.

Paraneoplastic neurologic disorders in small cell lung cancer are more common than appreciated

---in this study:

Methods: Two hundred sixty-four consecutive patients with biopsy-proven SCLC were recruited at the time of tumor diagnosis. All patients underwent full neurologic examination. Serum samples were taken prior to chemotherapy and analyzed for 15 neuronal antibodies…

Results: PNDs were quite prevalent (n = 24, 9.4%), most frequently Lambert-Eaton myasthenic syndrome (3.8%), sensory neuronopathy (1.9%), and limbic encephalitis (1.5%). Eighty-seven percent of all patients with PNDs had antibodies to SOX2 (62.5%), HuD (41.7%), or P/Q VGCC (50%), irrespective of their syndrome. Other neuronal antibodies were found at lower frequencies (GABAb receptor [12.5%] and N-type VGCC [20.8%]) or very rarely (GAD65, amphiphysin, Ri, CRMP5, Ma2, Yo, VGKC complex, CASPR2, LGI1, and NMDA receptor [all less than 5%]).

Conclusions: The spectrum of PNDs is broader and the frequency is higher than previously appreciated, and selected antibody tests (SOX2, HuD, VGCC) can help determine the presence of an SCLC.

Some background from the full text of the paper:

Currently almost half of all patients diagnosed with PNDs have associated SCLC,2 so this study is relevant to the broad epidemiology of these neurologic disorders. We found a higher frequency of PNDs (9.1% of SCLC) than previous SCLC surveys, perhaps because of the single-center prospective design with neurology input and high recruitment among the SCLC population. The findings suggest that PNDs in patients with SCLC may be underdiagnosed due to misattribution of symptoms; recognition of the disorders and their common antibody associations is important because the earlier the diagnosis is made, the better the oncologic and neurologic outcome.23,24

Via Clinical Correlations.

Causes of sudden cardiac death in athletes

From a large NCAA database as reported in Circulation:

Conclusions—The rate of SCD in National Collegiate Athletic Association athletes is high, with males, black athletes, and basketball players at substantially higher risk. The most common finding at autopsy is autopsy-negative sudden unexplained death. Media reports are more likely to capture high-profile deaths, and insurance claims are not a reliable method for case identification.

Point of care lung ultrasound

Here's a nice free full text review in the Annals of Intensive Care.

Right heart thrombus visualized on the echocardiogram (PE in transit)

The optimal treatment is controversial.