Gene expression analysis of human islets in a subject at onset of type 1 diabetes

Swollen islet cells have been repeatedly described at onset of type 1 diabetes, but the underlying mechanism of this observation, termed hydropic degeneration, awaits characterization. In this study, laser capture microdissection was applied to extract the islets from an organ donor that died at onset of type 1 diabetes and from an organ donor without pancreatic disease. Morphologic analysis revealed extensive hydropic degeneration in 73% of the islets from the donor with type 1 diabetes. Expression levels of genes involved in apoptosis, ER stress, beta cell function, and inflammation were analyzed in isolated and laser-captured islets by qPCR. The chemokine MCP-1 was expressed in islets from the donor with type 1 diabetes while undetectable in the control donor. No other signs of inflammation were detected. There were no signs of apoptosis on the gene expression level, which was also confirmed by negative immunostaining for cleaved caspase-8. There was an increased expression of the transcription factor ATF4, involved in transcription of ER stress genes, in the diabetic islets, but no further signs of ER stress were identified. In summary, on the transcription level, islets at onset of type 1 diabetes in which many beta cells display hydropic degeneration show no obvious signs of apoptosis, ER stress, or inflammation, supporting the notion that these cells are responding normally to high glucose and eventually succumbing to beta cell exhaustion. Also, this study validates the feasibility of performing qPCR analysis of RNA extracted from islets from subjects with recent onset of T1D and healthy controls by laser capture microdissection.

Spontaneous Coronary Artery Dissection and Papillary Muscle Rupture in Patient With Undiagnosed Vascular Ehler-Danlos Syndrome

We present the case of a woman with acute coronary syndrome on the basis of spontaneous coronary artery dissection causing a papillary muscle rupture with severe mitral regurgitation and acute heart failure. The patient subsequently underwent successful emergent surgery of both the mitral and tricuspid valves. Postoperatively, the patient was diagnosed with vascular Ehlers-Danlos syndrome. (Level of Difficulty: Advanced.)

Medical treatment of heart failure with renin-angiotensin-aldosterone system inhibitors and beta-blockers in aortic stenosis: association with long-term outcome after aortic valve replacement

Aims

There is a lack of robust data on the optimal medical treatment of heart failure in patients with severe aortic stenosis, with no randomized controlled trials guiding treatment. The study aimed to study the association between exposure to renin-angiotensin-aldosterone system (RAS) inhibitors or beta-blockers and outcome after aortic valve replacement in patients with aortic stenosis and heart failure.

Methods and results

The study included all patients with heart failure undergoing aortic valve replacement for aortic stenosis in Sweden between 2008 and 2016 (n = 4668 patients). Exposure to treatment was assessed by a continuous tracking of drug dispensations, and outcome events were all-cause mortality and hospitalization for heart failure collected from national patient registries. After adjustment for age, sex, atrial fibrillation, hypertension, diabetes mellitus, and prior myocardial infarction, Cox regression analysis showed that RAS inhibition was associated with a lower risk of all-cause mortality in patients with reduced left ventricular ejection fraction (LV-EF) [hazard ratio (HR) 0.58, 95% confidence interval (CI) 0.51-0.65] and preserved LV-EF (HR 0.69, 95% CI 0.56-0.85). Beta-blockade was associated with a lower risk of all-cause mortality in patients with reduced LV-EF (HR 0.81, 95% CI 0.71-0.92), but not in preserved LV-EF (HR 0.87, 95% CI 0.69-1.10). There was no association between RAS inhibition or beta-blockade and the risk of hospitalization for heart failure.

Conclusion

The RAS inhibition was associated with a lower all-cause mortality after valve replacement in patients with both reduced and preserved LV-EF. Beta-blockade was associated with lower all-cause mortality only in patients with reduced LV-EF.

[Papillary muscle rupture in acute coronary syndromes - a clinical chameleon with high mortality]

A paradigm shift in the treatment of acute coronary syndromes has led to a lower incidence of papillary muscle ruptures and other mechanical complications, with a risk of decreased vigilance for these serious complications. Sudden clinical deterioration with pulmonary edema and circulatory instability in the post infarction period should raise suspicion of papillary muscle rupture. Silent mitral regurgitation without an audible systolic murmur is not uncommon in the acute setting. Most cases of papillary muscle rupture develop high levels of CRP which should not be misinterpreted as signs of an infection. Studies from the modern reperfusion era shows a bimodal time course with the majority of cases presenting within 24 hours of the infarction and the rest primarily within the first week of the post infarction period. Early detection and diagnosis with cardiac ultrasound and prompt surgical treatment are important factors for prognosis.