Pathology of percutaneous interventions (PCI) in coronary arteries Allard van der Wal, MD.PhD; Pathologie AMC, Amsterdam, NL
Percutaneous Coronary Intervention (PCI) Definition: transcatheter opening of a stenosed / occluded coronary artery segment to restore or improve myocardial vascularization of symptomatic patients with ischemic heart disease Target lesion: usually (thrombosed) atherosclerotic plaque Tools: over many years: balloon dilatation (PTCA), directional or rotational atherectomy, laser angioplasty, thrombosuction, stents, bioscaffolds
Ischemic heart syndromes ANGINA PECTORIS stable angina ( excertional angina ) unstable angina MYOCARDIAL INFARCTION STEMI (transmural) non STEMI (non Q-wave, subendocardial) Acute coronary syndromes SUDDEN (CORONARY) CARDIAC DEATH ISCHEMIC HEART FAILURE
Ischemic heart syndromes ANGINA PECTORIS stable angina ( excertional angina ) unstable angina MYOCARDIAL INFARCTION STEMI (transmural) non STEMI (non Qwave, subendocardial) SUDDEN (CORONARY) CARDIAC DEATH ISCHEMIC HEART FAILURE
Released August 25th Not all myocardial infarctions relate to acute disrupted plaques Five distinct types of myocardial infarction need to be discriminated based on etiology, pathological parameters and related therapeutic consequences
Most cases Treated with early PCI From: Fourth universal definition of myocardial infarction (2018) Eur Heart J. Published online August 25, 2018. doi:10.1093/eurheartj/ehy462 Also including acute plaque hemorrhage
Elective PCI (not all cases) Myocardial ischemia in absence of coronary atherosthrombosis Fequency varies from 3-24% (10% in 25.872 pts) More in women, highe co morbidity, worse outcome (mortality, MACE) Eur Heart J. Published online August 25, 2018. doi:10.1093/eurheartj/ehy462
* Myocardial Infarction type 3: Suspecte MI related death; cardiac death in a setting suggestive for ichemic process, but who die before before biomarker or autopsy evidence of MI Separates fatal MI events from the large group of sudden deaths that may be cardiac (non ischemic) or non cardiac * Myocardial Infarction type 4a: PCI related MI, rise in cardiac biomarkers in combination with symptoms, ECG, imaging or autopsy evidence of ischemia after PCI - 4b: Stent thrombosis: thrombosis in combination with recurrence of symptoms and biomarker change - 4c: Stent restenosis: idem * Myocardial Infarction type 5: CABG related MI. Rise in cardiac biomarkers associated with bypass grafting (CABG) < 48hrs after procedure Pts with operative problems, difficult anastomosis, re operation
Acute coronary syndromes - therapeutic strategies - > 85% of PCI involve stent implantation - USA: 965.000 stent procedures in 2016 (1,6 mln in all vessels) - coronary stent market worldwide $9,5bln; 41% US, 29 Europe, Asian Pac fast growing
CORONARY STENTS Currently and previously United States Food and Drug Administration (FDA)-approved bare-metal stents (BMS) and drug-eluting Date of download: 9/5/2018 stents (DES). 14 N/A Copyright = not applicable. 2018 American Society of Anesthesiologists. All rights reserved.
DRUG ELUTING STENTS (DES) Sirolimus (A) chemical structure of the macrocylic lactone group of antiproliferative drugs. (B) mode of action of sirolimus: anti-inflammatory and antiproliferative Garg S, Serruys PW, Journal of the American College of Cardiology 2010;I0: 1-42
Thrombosuction / Thrombectomy STEMI or in stent thrombosis with significant thrombus burden
Directional Coronary Atherectomy (DCA) High rate of complications and restenosis Sometimes used in heavily calcified lesions http://dx.doi.org/10.1016/j.atherosclerosis.2005.03.049
( Reviewed by Torrado J, JACC 2018;71:1676 ) Pathology of coronary stents: navigating between thrombosis, restenosis, bleeding complications Balloon alone: early thrombosis, early and late recoil, restenosis (fibrocellular) : 30-50% Bleeding risk (GI) thrombosis Dual platelet therapy Bare Metal Stents: (early thrombosis), almost nothing restenosis: 30% Stent vascular modelling Drug Eluting Stents: (early thrombosis); almost nothing late / very late thrombosis (< 1-2 %) in stent neo atherosclerosis antiproliferative Drug eluting coatings
Figure from: Migra AK et al, J Clin Pathol 2006;59:232 Patent stent: Neointimal formation Restenosis Recurrence of ischemic symptoms + > 50 % angiographic stenosis)
Figure 1 sept 2003: DES stent ( Taxus pacltaxel eluting ) implantation - triple therapy ( OAC+ aspirin + clopidogrel ) april 2005: bleeding duodenal ulcer - triple therapy altered severe anginal symptoms followed by death
CD34 (endothelium) smooth muscle actin Drug eluting stent (DES): 1.5yrs very late thrombosis: * Delayed instent wound healing * Withdrawal of anti thrombotic therapy
Late Stent thrombosis - mechanisms SITE SPECIFIC - Delayed woundhealing (= withdrawal of pharmacotherapy) - Malapposition, protrusion of stent struts - inflammation / hypersensitivity - Stent fracture - neo atherosclerosis in stent (more in DES than in BMS) SYSTEMIC Diabetes, Small vessels, Renal Insufficiency, History of myocardial infarction, Current smoking, number of stents
F, 54yrs Stent in RCX Died 8 days later
Bioabsorbable scaffold
Everolimus eluting bioabsorbable vascular scaffold, 8 days after implantation Robin Kraak et al, JAHA 2015;4:11:e002551
Wiebes J et al, JACC 0214;64:2541
Bioresorbable Scaffolds versus Metallic Stents in Routine PCI (n= 924 vs 921) Joanna Wykrzykowska et al, NEJM 2017;376: 2319
SUMMARY * Not all ischemic events are amenable to PCI (different types, mechanisms, causes of Infarction and Angina) not all MI relate to coronary plaque rupture Autopsy of death following PCI is usually of great of interest for the Cardiologist: the navigation between restenosis, (late) thrombosis, hemorrhage, stent failure, pathology of new devices.