BME 301Review of Last TimeSlide 3Heart AttacksTissue Plasminogen ActivatorThrombolytics DrugsEffectiveness of ThrombolyticsCost-Effectiveness of ThrombolyticsSlide 9How Do We Treat Atherosclerosis?Slide 11Slide 12Slide 13Slide 14PTCA: EffectivenessSlide 16StentsSlide 18Drug Eluting StentsSlide 20Slide 21Slide 22Slide 23CABG ProcedureSlide 25Heart-Lung MachineHeart Lung MachineSlide 28Slide 29CABG EffectivenessInnovationsComparison of RX MethodsSlide 33What Would You Do?Prevention or Treatment?Progression of Heart DiseaseAssignments Due Next TimeBME 301Lecture SeventeenReview of Last TimeBurden of heart diseaseCardiovascular systemHow do heart attacks happen?Diagnosis of Atherosclerosis Blood tests Electrocardiograms (ECG) Stress tests Coronary angiography Ultrasounds Computed tomography (CT)Heart Attacks Treatment of Acute Occlusion:Thrombolytics DrugsTissue Plasminogen ActivatorTissue plasminogen.activator (tPA):A thrombolytic.agent (can dissolve blood clots)Approved for use in certain patients having heart attack or strokeClinical Studies:tPA and other.clot-dissolving agents can reduce the amount of damage to the heart muscle and save livesTo be effective, they must be given within a few hours after symptoms beginAdministered through an intravenous (IV) line in the arm by hospital personnelPatients treated within 90 minutes after onset of chest pain are one-seventh as likely to die compared to patients who receive therapy after 90 minutesThrombolytics DrugsRisks of thrombolytics:Intra-cranial hemorrhage Increased risk in those > age 70Patients may require further interventionCosts of thrombolytics:tPA = $2300Streptokinase = $320Effectiveness of ThrombolyticsClinical Trial:In 15 countries and 1081 hospitals41,021 patients with evolving myocardial infarction Randomly assigned to 4 different strategies:Streptokinase and subcutaneous heparinStreptokinase and IV heparinAccelerated tissue plasminogen activator (t-PA) and IV heparinCombo of streptokinase plus t-PA with IV heparinPrimary end point was 30-day mortalityResult: Streptokinase & subcut. heparin: 7.2% (stroke 0.49%)Streptokinase & IV heparin: 7.4% (stroke 0.54%)Accelerated t-PA & IV heparin: 6.3% (stroke 0.72%)Combo of both with IV heparin: 7.0% (stroke 0.94%)Cost-Effectiveness of ThrombolyticsTherapy Patient Group $ per yr life savedtPA Post MI high risk $3,600tPA Acute MI, large infarct, treatment started >2 hours post$24,200CounselingSmoking cessation $1300-$3900CABG Two vessel disease, severe angina$9,200-$42,500http://www.sciencedirect.com/science?_ob=ArticleURL&_aset=B-WA-A-A-A-MsSAYZA-UUA AUYWDCBYZYAUYUBBVZZYBWAUBWEUBAU&_rdoc=1&_fmt=full&_udi=B6T1048NJXK25&_coverDate=5%2F22%2F2003&_cdi=4876&_orig=search&_st=13&_sort=d&view=c&_acct=C000004378&_version 1&_urlVersion=0&_userid=108429&md5=5f493caa5f65762c23c0d90eaea8b92dHeart Attacks Treatment of AtherosclerosisHow Do We Treat Atherosclerosis? AngioplastyPTCA: EffectivenessCannot always successfully perform procedureDiffuse diseaseTotal occlusionCalcified diseaseRestenosisOccurs in 25-54% of patientsUsually occurs within 6 monthsHow Do We Treat Atherosclerosis? StentStentsStentsDrug Eluting Stentshttp://www.npr.org/features/feature.php?wfId=1452217How Do We Treat Atherosclerosis? CABGCABG ProcedurePatient is prepped, general anesthesiaChest access is gained, through sternumGraft vessel is retrievedExpose heart through pericardiumDivert blood through heart lung machineStop heartInsert graftReturn circulation to heartClose incisionHeart-Lung MachineThe heart-lung machine:Consists of a chamber that receives the blood from the bodyBlood is pumped by machine through an oxygenatorOxygenator removes CO2 and adds oxygenPump then pumps this newly oxygenated blood back to the bodyConnected to patient by a series of tubes that the surgical team placesHeart Lung MachineHeart Lung MachineHeart Lung MachineCABG Effectiveness2001: 516,000 CABG procedures performedProcedure takes 4-6 hours, 5-7 day hospital stayGrafts remain open & functioning for 10-15 yrsRisks:Heart attack (5%) Stroke (5%) (risk greatest in those over 70 years old) Death (1-2%) Sternal wound infection (1-4%)“Post-pericardiotomy syndrome“ (30%)Occurs few days to 6 months after surgerySymptoms are fever and chest painSome people report memory loss and loss of mental clarity or "fuzzy thinking" following CABGInnovationsOff-pump CABG:http://www.surgery.usc.edu/divisions/ct/videos-mpeg-offpumpcoronaryarterybypassgrafting.htmlClosed chest CABG:http://www.hsforum.com/stories/storyReader$1537Comparison of RX MethodsHospital Stay:CABG – 4-7 daysAngioplasty – 1-2 daysStent – 1-2 daysRestenosis:CABG – 5-6%, usually after 5 yearsAngioplasty – 25-45%, usually within 6 monthsStent – 15-20%, usually within 6 monthsComparison of RX MethodsCostCABG $35,000Angioplasty $17,000Stent $19,000Cost-effectivenessAdditive procedures:Within 5 years, 20-40% of patients have second PTCA, 25% have CABGAdditive costs:0 years: per patient costs of PTCA 30-50% those of CABG1 year: 50-60%3 years: 60-80%>3 years: >80%Moving Target ProblemWhat Would You Do?AngioplastyStentCABGPrevention or Treatment?http://www.nytimes.com/2004/03/21/health/21HEAR.htmlProgression of Heart DiseaseHigh Blood PressureHigh Cholesterol LevelsAtherosclerosisIschemiaHeart AttackHeart FailureAssignments Due Next Time
View Full Document