Cardiovascular Disaster in Hemodialysis patients Pattaraporn MD. Causes of death in prevalent dialysis patients 2008-2010 41.6% 26.5% Cardiovascular Disaster Sudden death • • • • Unexpected natural death Within a short time period >> 1-24 h Due to cardiac etiology New or more serious symptoms Possible Mechanisms Responsible for SD in HD Rapid electrolyte shifts/Hypervolemia QT dispersion Cardiac arrhythmia Cardiac arrest Inflammation cardiomyopathy •Myocardial interstitial fibrosis •Microvessel disease •CHF •CAD/MI •LVH/LV dysfunction Ischecmic heart disease Sympathetic overactivity Left ventricular Hypertrophy and Heart failure Concentric LV hypertrophy Eccentric LV hypertrophy Left ventricular Hypertrophy and Heart failure • LVH is an powerful indicator of mortality in dialysis patients • Presence of LVH >>> arrhythmia • Left ventricular systolic dysfunction >> arrhythmia Redaelli B: Lancet 1988;ii:305–309. Myocardial Interstitial fibrosis and Microvessel disease Inadequate capillary density + increased oxygen demand >> relative hypoxia >> fibrosis Myocardial Interstitial fibrosis and Microvessel disease • Fibrous tissue >> high electrical resistance • Development of atrial and ventricular reentry types of arrhythmias • Risk factor for the development of arrhythmias especially during the dialysis QT Dispersion • Difference between the longest and shortest QT intervals >> EKG 12 lead • Predict an increased risk of malignant arrhythmias • Normal value of QT dispersion in normal subjects was ≤40 ms • Dialysis patients with QT dispersion > 74 ms >> ventricular arrhythmias or SD • Low K+ and low Ca2+ >> acquired long QT syndrome Sympathetic overactivity • Heart rate >> myocardial demand supply >> cardiac hypertrophy and fibrosis • Decrease heart rate variability (reflecting autonomic dysfunction) >> increased risk for all-cause and SD in HD Inflammation • Marker : C-reactive protein, inhibit the hepatic generation of albumin • Reflection of vascular injury VS actually promotes vascular injury ? • High CRP level ( >6 mg/l ) : independent , predictive marker of future myocardial infarction – Herzig, K. A. et al. J. Am. Soc. Nephrol. 12, 814–821 (2001). • Inflammation could trigger SD >> atherosclerosis or direct effect on myocardium Other factors • • • • • • Rapid electrolyte shifts Hypervolemia Anemia Dyslipidemia Hypertension Calcium/phosphate deposition Avoiding low K dialysate & rapid electrolyte shifts ACEI and ARBs Prevention of Sudden Death Implantable defibrillators Beta-blocker Beta-blocker • Reduction of – Cardiac hypertrophy & fibrosis – Antifibrillary activity – Ventricular arrhythmia – Reduced risk of acute MI • Improve Heart rate variability • Increase in baroreflex sensitivity ACEI and ARBs • Reduction of – Cardiac hypertrophy & fibrosis – Fatal arrhythmia Avoiding low K dialysate & rapid electrolyte shifts: • To avoid – QT dispersion – Re‐entrant arrhythmias – Premature ventricular extrasystole (VES) Implantable defibrillators or Implantable Cardioverter Defibrillators (ICDs) • Most effective therapy for SCD in the general population • Indication – Survival of cardiac arrest due to VT or VF – Episode of sustained VT causing severe hemodynamic compromise – Episode of sustained VT without hemodynamic compromise + EF 35% – MI + EF 35% + nonsustained VT on 24-h ECG + inducible VT on electrophysiologic testing – MI + EF 30% QRS duration 120 ms on ECG Implantable defibrillators or Implantable Cardioverter Defibrillators (ICDs) • 42% risk reduction for death in dialysis patients with ICDs implanted according to conventional guidelines • Greater risk of device complications • No statistically increase >>> infection or fistula thrombosis – Kidney Int. 2005;68:818-825. Herzog CA et al. Kidney Int. 2005;68:818-825. Thank You