Øystein A. Vengen

The effect of aortic valve replacement on plasma B-type natriuretic peptide in patients with severe aortic stenosis--one year follow-up.

B‐type natriuretic peptide (BNP) is synthesized in cardiac tissue in response to increased wall stress and myocardial hypertrophy.

One single dose of histidine–tryptophan–ketoglutarate solution gives equally good myocardial protection in elective mitral valve surgery as repetitive cold blood cardioplegia: A prospective randomized study

OBJECTIVES Histidine-tryptophan-ketoglutarate (HTK-Custodiol) cardioplegic solution is administered as one single dose for more than 2 hours of ischemia. No prospective randomized clinical study has compared the effects of HTK and cold blood cardioplegia on myocardial damage in elective mitral valve surgery. Thus, the main aim of the present study was to examine whether one single dose of cold antegrade HTK gives as good myocardial protection as repetitive antegrade cold blood cardioplegia in mitral valve surgery. METHODS Eighty consecutive patients undergoing elective isolated mitral valve surgery for mitral regurgitation, with or without ablation for atrial fibrillation, were included in the study and randomized to HTK or blood cardioplegia. Markers of myocardial injury (troponin-T and creatine kinase MB) were analyzed at baseline and 7 hours, 1 day, 2 days, and 3 days after surgery. RESULTS No significant difference in creatine kinase MB and troponin-T between HTK and blood cardioplegia groups was found at any time point. There was a significant correlation between ischemic time and markers of myocardial injury in the HTK group only and significantly more spontaneous ventricular fibrillation after release of crossclamping in the HTK group. CONCLUSIONS One single dose of antegrade cold HTK cardioplegic solution in elective mitral valve surgery protects the myocardium equally well as repetitive antegrade cold blood cardioplegia.

Alterations in circulating activin A, GDF‐15, TGF‐β3 and MMP‐2, ‐3, and ‐9 during one year of left ventricular reverse remodelling in patients operated for severe aortic stenosis

Patients with aortic stenosis (AS) develop left ventricular remodelling with cardiomyocyte hypertrophy and increased fibrosis. Following aortic valve replacement (AVR) reverse remodelling usually takes place.

Cardiac tamponade caused by acute spontaneous coronary artery rupture.

Abstract  Acute spontaneous coronary artery rupture is rare and the diagnosis might be missed due to high risk of mors subita. We present three patients hospitalized with signs of cardiac tamponade due to acute spontaneous coronary artery rupture. All the three were successfully operated with evacuation of the pericardial hematoma, identification of the bleeding site, and hemostasis. The patients were examined with coronary angiography and computer tomography, and no underlying cause of the rupture was detected. In patients presenting with cardiac tamponade, acute spontaneous coronary artery rupture is a possible diagnosis.

Myocardial cooling with ice-slush provides no cardioprotective effects in aortic valve replacement

Objectives. Topical cooling of the heart with ice-slush has been widely used for myocardial protection. No prospective, randomized study has evaluated the effect of ice-slush on acknowledged markers (CK-MB, troponin-T) of myocardial damage during aortic valve replacement (AVR). This was the first aim of the present study. A second aim was to examine whether performing a study per se reduced myocardial damage. Design. Sixty patients undergoing AVR were receiving cold crystalloid antegrade cardioplegia every 20 min. Thirty patients were randomized to achieve additional topical cooling with ice-slush. CK-MB and troponin-T were compared between groups as well as to a group of patients undergoing AVR immediately prior to the study. Results. There were no significant differences in myocardial markers between patients with or without ice-slush. However, we found significantly higher levels of troponin-T and CK-MB in patients undergoing AVR prior to start of the study. Conclusions. Topical cooling with ice-slush does not provide additional cardioprotective effects. Comparison with an historical cohort indicates that administration of crystalloid cardioplegia following a rigid protocol might reduce myocardial damage.

Acute Chordae Rupture of the Mitral Valve Following Moderate Blunt Chest Trauma

Acute mitral regurgitation following traumatic rupture of the tendinous cords is very rare. A young woman is reported who suffered acute mitral regurgitation following moderate blunt chest trauma during cross-country skiing. She was successfully operated on with a mitral valve repair. Although historically, acute mitral regurgitation following traumatic papillary muscle rupture or rupture of tendinous cords is most commonly treated with a mitral valve prosthesis, mitral valve repair is possible in selected cases.

Plasma IL-18 and IL-18BP are altered differently in reverse remodeling following aortic valve replacement

Abstract Objectives. Patients with aortic stenosis (AS) develop left ventricular remodeling characterized by changes in extracellular matrix (ECM) and cardiomyocyte-hypertrophy. Aortic valve replacement (AVR) reverses this process (reverse remodeling). We examined plasma levels of interleukin-18 (IL-18) and its binding protein (IL-18BP) before and after AVR for AS since these mediators have been shown experimentally to exert effects on myocardial remodeling. Design. Plasma levels of IL-18 and IL-18BP were analyzed in 22 patients with AS undergoing AVR, preoperatively, two days, six and 12 months postoperatively. Echocardiography and functional testing were performed. Results. IL-18BP was significantly increased by 28% and 15% at two days and six months after AVR, compared to preoperative values. In contrast, IL-18 showed a later peak (increased by 24% at 12 months postoperatively) when IL-18BP was normalized. IL-18 correlated positively with deceleration time (R = 0.44) at this time-point which might indicate an association with diastolic function. Conclusions. We report for the first time that plasma IL-18 and IL-18BP are differentially regulated after AVR for AS with an early increase in IL-18BP postoperatively followed by a later peak in IL-18 at 12 months. Given the known effects of these mediators on myocardial remodeling and function, they might play a role in the reverse and remodeling process associated with AVR.

Latitude of the study place and age of the patient are associated with incidence of mediastinitis and microbiology in open-heart surgery: a systematic review and meta-analysis.

Objective We aimed to summarize the pooled frequency of mediastinitis following open-heart surgery caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and Gram-negative bacteria. Design This study was a systematic review and a meta-analysis of prospective and retrospective cohort studies. Materials and methods We searched the literature, and a total of 97 cohort studies were identified. Random-effect model was used to synthesize the results. Heterogeneity between studies was examined by subgroup and meta-regression analyses, considering study and patient-level variables. Small-study effect was evaluated. Results Substantial heterogeneity was present. The estimated incidence of mediastinitis evaluated from 97 studies was 1.58% (95% confidence intervals [CI] 1.42, 1.75) and that of Gram-positive bacteria, Gram-negative bacteria, and MRSA bacteria evaluated from 63 studies was 0.90% (95% CI 0.81, 1.21), 0.24% (95% CI 0.18, 0.32), and 0.08% (95% CI 0.05, 0.12), respectively. A meta-regression pinpointed negative association between the frequency of mediastinitis and latitude of study place and positive association between the frequency of mediastinitis and the age of the patient at operation. Multivariate meta-regression showed that prospective cohort design and age of the patients and latitude of study place together or in combination accounted for 17% of heterogeneity for end point frequency of mediastinitis, 16.3% for Gram-positive bacteria, 14.7% for Gram-negative bacteria, and 23.3% for MRSA bacteria. Conclusion Evidence from this study suggests the importance of latitude of study place and advanced age as risk factors of mediastinitis. Latitude is a marker of thermally regulated bacterial virulence and other local surgical practice. There is concern of increasing risk of mediastinitis and of MRSA in elderly patients undergoing sternotomy.

Cardiac Responses to Increased Contractility: Digital Simulation and Mathematical Analysis

Abstract By models of the circulation, we analyzed the responses to a rise in contractility in one chamber of the heart. The study was initiated because one-sided inotropic stimulation revealed different responses in the two ventricles of the in situ pig heart. In a simple two-compartment model of the circulation, both numerical data analysis and an analytical mathematical approach revealed that decrements in both maximal and minimal heart chamber volumes were to be expected when contractility was increased. This response also appeared in the right ventricle of the in situ pig heart when the effect of increased contractility in the right atrium was abolished by simultaneous atrial-and ventricular contraction. A computer-based seven compartment model of the circulation predicted these responses and offered two alternative explanations for the different-directed changes in left- and right ventricular end-diastolic volumes when the respective sides were inotropically stimulated. First, some degree of right ventricular dilation followed the rise in pulmonary artery pressure during elevations of right-side contractility. Second, right atrial function was better preserved than left atrial function; increased contractility in the right side of the heart caused end-diastolic dilation of the right ventricle both at normovolemia, and even more at hypervoemia, but this response vanished at hypovolemia.