Management of Acute Coronary Syndromes in Patients with Diabetes: Implications of the FREEDOM Trial

Background

Diabetes mellitus (DM) is a powerful independent risk factor for multivessel, diffuse coronary artery disease (CAD). The optimal coronary revascularization strategy in DM is not clearly defined, but past trials have suggested an advantage for coronary artery bypass grafting (CABG). Recently, the Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease (FREEDOM) trial found patients randomized to CABG had lower rates of death and myocardial infarction (MI) compared with those randomized to percutaneous coronary intervention (PCI).

Objective

This article reviews the contemporary management of patients with DM presenting with acute coronary syndromes, particularly ST-elevation MI, in the post-FREEDOM era.

Methods

We undertook a comprehensive review of published literature addressing trials in this field performed to address current knowledge both in the pre- and post-FREEDOM era.

Results

The implications of FREEDOM for patients with acute coronary syndrome are that CABG provides a significant benefit, compared with PCI with drug-eluting stents, to patients with DM and multivessel coronary artery disease; and that patients similar to those enrolled in FREEDOM should receive CABG in preference to PCI. The relevance of FREEDOM’s findings to the large proportion of patients who would not meet inclusion criteria—including patients with an acute coronary syndrome undergoing an early or emergent invasive strategy, remains uncertain.

Discussion

FREEDOM’s outcomes have generated uncertainty regarding best practice once thrombolysis in myocardial infarction grade 3 flow is re-established in patients with DM and multivessel disease. Current interventional guidelines recommend optimally treating the culprit artery; however, decisions made at the time of revascularization influence future revascularization strategies, particularly stent choice and resultant P2Y₁₂ receptor antagonist therapy. The preferred method for future revascularization may be questioned if the patient's residual coronary stenoses do not, post-PCI, meet the FREEDOM inclusion criteria, or where the left anterior descending artery is the infarct-related artery, and after left anterior descending artery PCI the patient would not receive an internal mammary graft. The management of residual disease and the preferred (further) revascularization strategy needs to be tested in an appropriately powered randomized trial.

Conclusions

The optimal revascularization strategy in patients with acute coronary syndrome, diabetes, and multivessel disease, in particular those with ST elevation, is unclear, and not guided by level A (or B) evidence. Currently CABG is favored over PCI, and an individually tailored, collaborative approach, guided by a multidisciplinary heart team, should be employed.     

Alport's syndrome and the eye

Alport's syndrome comprises hereditary deafness, nephritis and ocular abnormalities. The features of Alport's syndrome are illustrated by a family with Alport's syndrome and hereditary oesophageal leiomyomatosis. The evidence that Alport's syndrome is due to a widespread basement membrane disorder is noted. Treatment of anterior lenticonus, the principal ocular abnormality, by lensectomy and intraocular lens insertion is recommended.     

Difficult intubation in an infant with Pierre Robin(r) syndrome and concomitant tongue tie

Intubation and airway difficulties may be assumed in infants with Pierre Robin syndrome. We report a case of a six month old cleft palate repair who also had a tongue tie which compounded the problem. He was eventually intubated using the two anaesthetist technique. The contribution of the tongue tie is assessed.     

Reduction in the Shivering Threshold Is Proportional to Spinal Block Height

Background: Hypothermia is nearly as common, and may be as severe, during spinal and epidural anesthesia as during general anesthesia. The authors have proposed that thermoregulatory failure results when regional anesthesia increases apparent leg skin temperature to a level far exceeding actual leg skin temperature. Extensive dermatomal blocks will alter thermal input to the hypothalamus from a greater skin-surface area more than less extensive ones and thus might be expected to impair central thermoregulatory control more. Accordingly, they tested the hypothesis that reduction in the shivering threshold is directly related to the number of dermatomes blocked during spinal anesthesia.

Methods: Eleven men, aged 62+/-6 yr (mean+/-SD), undergoing urologic surgery were studied. Ice-cold lactated Ringer's solution was administered intravenously before spinal blockade, and the shivering threshold (triggering core temperature) was established. Spinal anesthesia then was induced using a randomly assigned dose of 0.5% bupivacaine (2-4 ml). Again, sufficient cold lactated Ringer's solution was given to induce shivering. Tympanic membrane, ambient and skin temperatures were measured, and extent of block was defined by loss of temperature discrimination. Presence of shivering was evaluated by a blinded observer. Mean upper-body skin and ambient temperatures, cooling rates and intravenous fluid volumes at the two thresholds were compared using paired, two-tailed t tests (P < 0.05). Linear regression defined the relationship between reduction in shivering threshold and the number of dermatomes blocked.

Results: There were no significant differences between mean upper-body skin and ambient temperatures, cooling rates or intravenous fluid volumes at the control and spinal shivering thresholds. Spinal anesthesia reduced the shivering threshold in direct relation to the number of dermatomes blocked: Delta threshold = 0.74 - 0.06 (dermatomes blocked); r2 = 0.58, P < 0.006.     

A Case of Spontaneous Resolution of Nonimmune Hydrops Fetalis

Summary: Spontaneous intrauterine resolution of severe nonimmune hydrops fetalis has been rarely reported in the literature. A case of severe fetal hemolytic anaemia with hydrops fetalis but subsequent spontaneous resolution is reported along with a discussion of possible aetiologies.