Giovanni Peretto

Postoperative Arrhythmias after Cardiac Surgery: Incidence, Risk Factors, and Therapeutic Management

Arrhythmias are a known complication after cardiac surgery and represent a major cause of morbidity, increased length of hospital stay, and economic costs. However, little is known about incidence, risk factors, and treatment of early postoperative arrhythmias. Both tachyarrhythmias and bradyarrhythmias can present in the postoperative period. In this setting, atrial fibrillation is the most common heart rhythm disorder. Postoperative atrial fibrillation is often self-limiting, but it may require anticoagulation therapy and either a rate or rhythm control strategy. However, ventricular arrhythmias and conduction disturbances can also occur. Sustained ventricular arrhythmias in the recovery period after cardiac surgery may warrant acute treatment and long-term preventive strategy in the absence of reversible causes. Transient bradyarrhythmias may be managed with temporary pacing wires placed at surgery, but significant and persistent atrioventricular block or sinus node dysfunction can occur with the need for permanent pacing. We provide a complete and updated review about mechanisms, risk factors, and treatment strategies for the main postoperative arrhythmias.

Role of the Renin-Angiotensin-Aldosterone system in the pathogenesis of atherosclerosis

Renin-angiotensin-aldosterone (RAAS) is a hormone system which acts on multiple physiologic pathways primarily by regulating blood pressure and fluid balance, but also by local autocrine and paracrine actions. In pathophysiologic conditions RAAS also contributes to the development of atherosclerosis and its various manifestations, both directly and indirectly through the actions on other systems. RAAS mainly acts as a promoter of atherosclerosis by its action on vessels, and by promoting the development of hypertension, insulin resistance and diabetes, obesity, vascular and systemic inflammation. As RAAS plays a key role in the pathogenesis of cardiovascular diseases, RAAS genes have been extensively studied as candidate genes for atherosclerosis and coronary artery disease. Several polymorphisms of its genes have been found to be in relationship with atherosclerosis and cardiovascular diseases. In this review we will discuss these issues and present the most recent advances about this topic.

Serum uric acid on admission predicts in-hospital mortality in patients with acute coronary syndrome

BACKGROUND Despite the association between uric acid and cardiovascular disease has been known for decades, the prognostic value of serum uric acid (UA) in all clinical manifestations of acute coronary syndrome (ACS), namely ST-elevation myocardial infarction (STEMI), NSTEMI and unstable angina, has not been definitively assessed. METHODS This retrospective analysis included patients from previous SPAI and FAMI studies with the aim to investigate the association between serum uric acid and major adverse cardiovascular events at 180days from hospital admission. RESULTS 1548 patients were considered and divided in four groups, according UA concentration. Uricemia was significantly associated with gender, BMI, arterial hypertension, HDL-cholesterol, triglycerides, metabolic syndrome and glomerular filtration rate in univariate analysis. Multivariate logistic regression indicated that UA >6.0mg/dL on admission increased the risk of in-hospital mortality in overall population (OR 2.9, 95%CI 1.4-6.1; p=0.0057) and in patients with de novo ACS (OR 3.2, 95%CI 1.5-6.8; p=0.0033). Comparable results were also obtained after adjusting the model for age, gender, body mass index, glomerular filtration rate, metabolic syndrome, acute revascularization and ethnicity. A positive correlation was observed between UA and C reactive protein concentrations in in-hospital deaths only (rho 0.41, p=0.027). CONCLUSION In patients with acute coronary syndrome, uricemia levels above the current international reference limit (6.0mg/dl) were associated with in-hospital mortality, independently from ethnicity and renal function.

Clinical Presentation and Outcome in a Contemporary Cohort of Patients with Acute Myocarditis: The Multicenter Lombardy Registry

Background: There is controversy about the outcome of patients with acute myocarditis (AM), and data are lacking on how patients admitted with suspected AM are managed. We report characteristics, in-hospital management, and long-term outcome of patients with AM based on a retrospective multicenter registry from 19 Italian hospitals. Methods: A total of 684 patients with suspected AM and recent onset of symptoms (<30 days) were screened between May 2001 and February 2017. Patients >70 years of age and those >50 years of age without coronary angiography were excluded. The final study population comprised 443 patients (median age, 34 years; 19.4% female) with AM diagnosed by either endomyocardial biopsy or increased troponin plus edema and late gadolinium enhancement at cardiac magnetic resonance. Results: At presentation, 118 patients (26.6%) had left ventricular ejection fraction <50%, sustained ventricular arrhythmias, or a low cardiac output syndrome, whereas 325 (73.4%) had no such complications. Endomyocardial biopsy was performed in 56 of 443 (12.6%), and a baseline cardiac magnetic resonance was performed in 415 of 443 (93.7%). Cardiac mortality plus heart transplantation rates at 1 and 5 years were 3.0% and 4.1%. Cardiac mortality plus heart transplantation rates were 11.3% and 14.7% in patients with complicated presentation and 0% in uncomplicated cases (log-rank P<0.0001). Major AM-related cardiac events after the acute phase (postdischarge death and heart transplantation, sustained ventricular arrhythmias treated with electric shock or ablation, symptomatic heart failure needing device implantation) occurred in 2.8% at the 5-year follow-up, with a higher incidence in patients with complicated forms (10.8% versus 0% in uncomplicated AM; log-rank P<0.0001). &bgr;-Adrenoceptor blockers were the most frequently used medications both in complicated (61.9%) and in uncomplicated forms (53.8%; P=0.18). After a median time of 196 days, 200 patients had follow-up cardiac magnetic resonance, and 8 of 55 (14.5%) with complications at presentation had left ventricular ejection fraction <50% compared with 1 of 145 (0.7%) of those with uncomplicated presentation. Conclusions: In this contemporary study, overall serious adverse events after AM were lower than previously reported. However, patients with left ventricular ejection fraction <50%, ventricular arrhythmias, or low cardiac output syndrome at presentation were at higher risk compared with uncomplicated cases that had a benign prognosis and low risk of subsequent left ventricular systolic dysfunction.

The predictive role of renal function and systemic inflammation on the onset of de novo atrial fibrillation after cardiac surgery

Background The association between postoperative atrial fibrillation (POAF) and renal function was previously grounded in patients undergoing coronary artery bypass grafting through unknown mechanisms. We aim to investigate the association between renal function and POAF in a cohort composed mostly of patients undergoing valve surgery and to explore the role of inflammation as a pathogenic mechanism linking renal dysfunction and arrhythmogenesis. Methods Altogether 444 patients who underwent cardiac surgery without previous history of atrial fibrillation were analysed. Serum creatinine and high sensitivity C-reactive protein (hs-CRP) concentrations were obtained at baseline and on the 3rd, 8th and 15th postoperative day; estimated glomerular filtration rate (eGFR) was calculated by the Modified Diet Renal Disease (MDRD) formula. Patients were divided into three groups on the basis of baseline eGFR. Results Overall, 173 (39%) patients developed POAF, 29.5% in the group with normal eGFR (≥90 ml/min/1.73 m2), 43.3% among patients with eGFR 60–90 ml/min/1.73 m2 and 55.6% in the group with eGFR ≤60 ml/min/1.73 m2. Patients developing POAF had lower eGFR on all the samples. At baseline preoperatively hs-CRP levels did not differ in the two groups. On multivariate analysis, age and eGFR were identified as independent predictors of POAF. The risk of POAF progressively increased from mild impairment (odds ratio (OR) 1.59, 95% confidence interval (CI) 1.01–2.50) to severe reduction of renal function (OR 2.35, 95% CI 1.25–4.48). Conclusions Age and eGFR were identified as the strongest predictors of POAF in a population largely composed of valve surgery patients. Renal function, even from early stage, is independently associated with the increasing risk of developing POAF.

The value of the 12-lead electrocardiogram in localizing the scar in non-ischaemic cardiomyopathy.

AIMS Patients with non-ischaemic cardiomyopathy (NICM) and ventricular tachycardia can be categorized as anteroseptal (AS) or inferolateral (IL) scar sub-types based on imaging and voltage mapping studies. The aim of this study was to correlate the baseline electrocardiogram (ECG) with endo-epicardial voltage maps created during ablation procedures and identify the ECG characteristics that may help to distinguish the scar as AS or IL. METHODS AND RESULTS We assessed 108 baseline ECGs; 72 patients fulfilled criteria for dilated cardiomyopathy whereas 36 showed minimal structural abnormalities. Based on the unipolar low-voltage distribution, the scar pattern was classified as predominantly AS (n = 59) or IL (n = 49). Three ECG criteria (PR interval < 170 ms or QRS voltage in inferior leads <0.6 mV or a lateral q wave) resulted in 92% sensitivity and 90% specificity for predicting an IL pattern in patients with preserved ejection fraction (EF). The four-step algorithm for dilated cardiomyopathy included a paced ventricular rhythm or PR > 230 ms or QRS > 170 ms or an r ≤ 0.3 mV in V3 having 92 and 81% of sensitivity and specificity, respectively, in predicting AS scar pattern. A significant negative correlation was found between the extension of the endocardial unipolar low voltage area and left ventricular EF (rs = -0.719, P < 0.001). The extent of endocardial AS unipolar low voltage was correlated with PR interval and QRS duration (rs = 0.583 and rs = 0.680, P < 0.001, respectively) and the IL epicardial unipolar low voltage with the mean voltage of the limb leads (rs = -0.639, P < 0.001). CONCLUSION Baseline ECG features are well correlated with the distribution of unipolar voltage abnormalities in NICM and may help to predict the location of scar in this population.

Updated Clinical Overview on Cardiac Laminopathies: An Electrical and Mechanical Disease

ABSTRACT Cardiac laminopathies, associated with mutations in the LMNA gene, encompass a wide spectrum of clinical manifestations, involving electrical and mechanical alterations of cardiomyocytes. Thus, dilated cardiomyopathy, bradyarrhythmias and atrial or ventricular tachyarrhythmias may occur in a number of combined phenotypes. Nowadays, some attempt has been made to identify clinical predictors for the most life-threatening complications of LMNA-associated heart disease, i.e. sudden cardiac death and end-stage heart failure. The goal of this manuscript is to combine the most recent evidences in an updated review to show the state-of-the-art of such a complex disease group. This is supposed to be the starting point to collect more data and design new ad hoc studies to identify clinically useful predictors to stratify risk in mutation carriers, including probands and their asymptomatic relatives.

PHARMACOGENOMIC IMPLICATIONS OF RENIN ANGIOTENSIN ALDOSTERONE SYSTEM INHIBITION IN ST-ELEVATION MYOCARDIAL INFARCTION

Background: A complex network of gene-environment interactions may be related to myocardial infarction. To date, several single nucleotide polymorphisms (SNPs) have been investigated as potential determinants in terms of predisposition, prognosis and response to therapy, but with no definite

Pharmacological and nonpharmacological treatment after cardiac surgery.

Open-heart surgery has become a common procedure. Postcardiac surgery management is a critical issue and represents a crucial period in terms of physical recovery. Cardiac rehabilitation is increasingly considered as an integral component of the continuum of care for patients with cardiovascular disease. Its usefulness is now widely accepted, and therefore, it is recommended in most contemporary cardiovascular clinical practice guidelines. Similarly, early pharmacological management can modulate the pathophysiological alterations after cardiac surgery, leading to an improvement in the early and long-term outcome. In this review, we will present recent advances in postcardiac surgery management, focusing on the pathophysiology of the perioperative period and on recent evidences in pharmacological and rehabilitative strategies.

Cardiotoxicity in oncology and coronary microcirculation: future challenges in theranostics

Many of the patients undergoing chemotherapy or radiotherapy for cancer are at increased risk of developing cardiovascular diseases. Recent evidence suggests that cardiac dysfunction and subsequent heart failure are mainly due to vascular toxicity rather than only to due to myocyte toxicity. However, not all of the vascular toxicity of cancer therapies can be explained by epicardial coronary artery disease. In fact, in the last decades, it has been found that myocardial ischemia may occur as a consequence of structural or functional dysfunction of the complex network of vessels, which cannot be seen by a coronary angiography: the coronary microcirculation. Nowadays many diagnostic and therapeutic options are available both in coronary microvascular dysfunction and cardio-oncology. Aim of this review is to suggest future theranostic implications of the relationship between cardiotoxicity in oncology and coronary microvascular dysfunction, showing common pathophysiologic mechanisms, proposing new diagnostic approaches and therapeutic options for cardioprotection.