Thoracic aortic aneurysm, as occurs in Marfan syndrome, is generally asymptomatic until dissection or rupture, requiring surgical intervention as the only available treatment. Here, we show that nitric oxide (NO) signaling dysregulates actin cytoskeleton dynamics in Marfan Syndrome smooth muscle cells and that NO-donors induce Marfan-like aortopathy in wild-type mice, indicating that a marked increase in NO suffices to induce aortopathy. Levels of nitrated proteins are higher in plasma from Marfan patients and mice and in aortic tissue from Marfan mice than in control samples, indicating elevated circulating and tissue NO. Soluble guanylate cyclase and cGMP-dependent protein kinase are both activated in Marfan patients and mice and in wild-type mice treated with NO-donors, as shown by increased plasma cGMP and pVASP-S239 staining in aortic tissue. Marfan aortopathy in mice is reverted by pharmacological inhibition of soluble guanylate cyclase and cGMP-dependent protein kinase and lentiviral-mediated Prkg1 silencing. These findings identify potential biomarkers for monitoring Marfan Syndrome in patients and urge evaluation of cGMP-dependent protein kinase and soluble guanylate cyclase as therapeutic targets.

Background To evaluate the influence of subclinical hypothyroidism (SCH) on the development of postoperative atrial fibrillation (AF) in patients undergoing aortic valve replacement surgery with extracorporeal circulation. Methods A prospective study in a tertiary hospital between July 2005 and December 2013 in which all patients undergoing aortic valve replacement with no other valve surgery were consecutively included. Patients who were in preoperative sinus rhythm were selected and they underwent thyroxine (T4) and thyroid-stimulating hormone determination in the month before surgery. Postoperative AF was defined as the development of AF during hospital admittance. Descriptive analysis and binary logistic regression were performed for the target variable. Results A total of 467 patients were studied, with 35 cases of SCH. The incidence of postoperative AF was 57% in the group with SCH versus 30.3% (p = 0.001) in the group without hypothyroidism, without significant differences in other postoperative complications. In the logistic regression analysis, the independent predictors of postoperative AF were SCH, age, and aortic clamping time. SCH multiplies the odds ratio of postoperative AF by 3.14 (95% confidence interval: 1.24-7.96). Conclusion SCH behaves like a risk factor for the development of postoperative AF in patients undergoing aortic valve replacement with extracorporeal circulation. Other studies are needed to determine whether preoperative T4 replacement therapy and/or more aggressive AF prophylaxis can prevent this complication in patients undergoing aortic valve replacement.

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Myocardial ischaemia due to extrinsic left main coronary artery compression is unusual. Most cases are related to pulmonary hypertension with severe main pulmonary artery dilatation. An extremely rare cause is a left sinus of Valsalva aneurysm (SVA). We describe the case of a patient diagnosed of left SVA after a coronary angiography and aortography, whose initial clinical manifestation was an acute coronary syndrome complicated with an out-hospital resuscitated sudden cardiac death.Keywords: Aneurysm (aortic root) • Aortic operation • Coronary artery bypass grafts surgery CASE REPORTOn November 2011, a previously asymptomatic hypercholesterolemic 55-year old man was referred to our hospital for surgical repair after an out-of-hospital resuscitated sudden cardiac death after finishing a marathon caused by left main coronary artery (LMCA) compression by a sinus of Valsalva aneurysm (SVA). No neurological sequelae remained. He had no additional cardiovascular risk factors. On admission, physical examination and laboratory data, including cardiac enzyme levels, revealed no abnormalities. On chest X-ray, no increased cardiothoracic ratio or focal lung lesions were demonstrated and no ischaemic changes were suggested on EKG.Transthoracic and transoesophageal echocardiography demonstrated a 50-mm aortic root aneurysm with an asymmetrically enlarged left coronary sinus of Valsalva with normal heart valve function, confirmed during aortography ( Fig. 1A and B). On coronary angiography (Fig. 1C), an associated severe (70%) concentric ostial and proximal LMCA stenosis was observed, with no other significant coronary stenosis, and urgent surgical correction was indicated. Intraoperative findings included a global dilated aortic root and an asymmetric left SVA with diffuse calcified plaques and intimal ulcers extended through aortic annulus, making very difficult valve-preserving aortic root reconstruction, so we decided to perform an aortic root and valve replacement with a mechanical composite valve conduit (St Jude Medical, St Paul, MN, USA). The LMCA was compressed and enlarged by the aneurysm with a long proximal portion inlaid in its wall. The left anterior descending artery had an intramyocardial distribution on its proximal and mid portions. During coronary button tailoring, the LMCA was unavoidably transected and therefore was ligated. Coronary reconstruction included right coronary artery reimplantation and coronary artery bypass grafting (CABG) to the distal left anterior descending artery and first obtuse marginal branch with both internal thoracic arteries. On weaning of cardiopulmonary bypass ischaemic ST-segment changes were observed on precordial leads with associated echocardiographic basal anterior acinesia, and a supplemental vein graft to the first diagonal branch was performed. Afterwards, the postoperative course was uneventful. Anatomopathological analysis of the aortic root wall demonstrated atherosclerotic changes.At 3-month follow-up, the patient remained asymptomatic on New York Heart Asso...