Heart rate variability： a new tool to predict complications in adult cardiac surgery

Heart rate variability （HRV） refers to the variations between consecutive heartbeats, which depend on the continuous modulation of the sympathetic and parasympathetic branches of the autonomic nervous system. HRV has been shown to be effective as a predictor of risk after myocardial infarction and an early warning sign of diabetic neuropathy, and in the cardiology setting is now recognized to be a useful tool for risk-stratification after hospital admission and after discharge. Recent evidences suggest that HRV analysis might predict complications even in patients undergoing cardiac surgery, and the present review summarizes the importance of HRV analysis in adult cardiac surgery and the perspectives for HRV use in current clinical practice. Although future larger studies are warranted before HRV can be included into daily clinical practice in adult cardiac surgery, HRV is a novel tool which might detect autonomic instability in the early postoperative phase and during hospital stay, thus predicting or prompt-diagnosing many of the post-operative complications.

The role of extracellular matrix in age-related conduction disorders： a forgotten player？

Cardiovascular aging is a physiological process gradually leading to structural degeneration and functional loss of all the cardiac and vascular components. Conduction system is also deeply influenced by the aging process with relevant reflexes in the clinical side. Age-related arrhythmias carry significant morbidity and mortality and represent a clinical and economical burden. An important and unjustly unrecognized actor in the pathophysiology of aging is represented by the extracellular matrix （ECM） that not only structurally supports the heart determining its mechanical and functional properties, but also sends a biological signaling regulating cellular function and maintaining tissue homeostasis. At the biophysical level, cardiac ECM exhibits a peculiar degree of anisotropy, which is among the main determinants of the conductive properties of the specialized electrical conduction system. Age-associated alterations of cardiac ECM are therefore able to profoundly affect the function of the conduction system with striking impact on the patient clinical conditions. This review will focus on the ECM changes that occur during aging in the heart conduction system and on their translation to the clinical scenario. Potential diagnostic and therapeutical perspectives arising from the knowledge on ECM age-associated alterations are further discussed.

Off-pump coronary artery bypass grafting versus optimal medical therapy alone：effectiveness of incomplete revascularization in high risk patients

BackgroundGeriatric patients with multivessel coronary artery disease （CAD） are a challenging group to treat; these cases elicit dis-cussion within heart teams regarding the actual benefit of undertaking major surgery on these patients and often lead to abandon the surgical option. Percutaneous procedures represent an important option, but coronary anatomy may be unfavorable. Off-pump coronary artery bypass （OPCAB） provides good quality graft on left anterior descending （LAD） without exposing the patient to cardiopulmonary bypass, and might be the ideal choice in patients with multiple comorbidities, not eligible to percutaneous or on-pump procedures. The objective of this study was to compare survival during a mid-term follow-up in high-risk patients with no percutaneous alternative, either treated with OPCAB or discharged in medical therapy.MethodsWe retrospectively evaluated from June 2008 to June 2013, 83 high-risk patients with multivessel CAD were included： 42 were treated with incomplete off-pump revascularization using left internal mammary artery （LIMA） on LAD; 41 were discharged in optimal medical therapy （OMT）, having refused surgery. Follow-up ended in March 2015, with a telephonic interview. Primary endpoint was survival from all-cause mortality; secondary endpoints were survival from cardiac-related mortality and freedom from non-fatal major adverse cardiac events （MACEs）.ResultsDuring follow up, 11 deaths in OPCAB group and 27 deaths in OMT group occurred. Death was due to cardiac factors in 6 and 15 patients, respectively. MACEs were observed in 6 patients in OPCAB group and in 4 patients in OMT group. With regards to survival from all-cause mortality, patients who underwent OPCAB survived more than those dis-charged in OMT （Log Rank ＆lt; 0.001）, and OMT group carries a propensity score-adjusted hazard ratio of 3.862 （P ＆lt; 0.001）. With regards to survival from cardiac-related events, patients who underwent OPCAB survived more than those discharged in OMT （Log Rank = 0.002）, and OMT group carries a propensity score-adjusted hazard ratio of 3.663 （P = 0.010）. There is no statistically significant difference concerning freedom from MACEs （Log Rank = 0.273）.ConclusionsFor high-risk patients with multivessel CAD, not eligible to on-pump complete revascularization surgery or percutaneous procedures, incomplete revascularization with OPCAB LIMA-on-LAD offers benefits in survival when compared to OMT alone.

A Surgical Perspective on Ischemic Mitral Regurgitation: Tethering or Prolapse? Going Back to Papillary Muscles Anatomy. What the Surgeons Really Need to Know

More than one third of patients with ischemic mitral regurgitation (IMR) present a valve prolapse whose mechanism is subtended by a papillary injury. The recent literature is pointing at a regional ventricular injury or wall motion abnormality rather than a global LV dysfunction as responsible for IMR and the presence of localized valve prolapse related to papillary dysfunction is additionally supporting this idea. Leaflet tethering or prolapse in these patients is subtended by lesion of the papillary muscle (PM) per se rather than its dysfunction secondary to regional and global ventricle enlargement. Identification of this type of lesion is difficult and can be overlooked. Morphological characteristics and anatomical variability of the papillary muscles determine their different susceptibility ischemic damage and dysfunction. Pioneering work in mitral anatomy shows a range of morphological diversity of PM anatomy and leads to an anatomical classification with important implications in IMR surgery. New methods of investigation, as multidetector computed tomography or magnetic resonance provide a very accurate and proper identification of the morphological pattern of the subvalvular apparatus, which is crucial for a long-lasting and successful surgical correction. The involvement of PM in the pathophysiology of IMR not only in terms of their functional anomaly, but also of their effective anatomical aspects and characteristics is increasingly emerging. The modern advancements of imaging techniques can guide the preoperative surgical planning and the surgeon needs to be aware of morphological features of the subvalvular apparatus and combine these findings with echographic functional parameters before embarking in complex mitral repairs.