Evaluation of Suspected CAD in 2011 Nader M. (Nader) Banki, MD - PowerPoint PPT Presentation

RWC Physicians’ Conference Evaluation of Suspected CAD in 2011 Nader M. (Nader) Banki, MD Xiushui (Mike) Ren, MD March 4, 2011

Disclosure of Relevant Financial Relationships  Under the ACCME Standards for Commercial Support, everyone who is in a position to control the content of an education activity must disclose all relevant financial relationships with any commercial interest. A “commercial interest” includes any proprietary entity producing health care goods or services, with the exemption of non-profit or government organizations and non-health care related companies. A financial relationship is relevant if it pertains to the activity’s content matter including any related health care products or services to be discussed or presented.  Drs. Banki and Ren have disclosed that they have no relevant relationships with commercial or industry organizations. The CME Department has reviewed their disclosure information for the planner(s) and/or committee/faculty for this program and they do not have relationships that present a relevant conflict of interest.

Outline  Indications for “stress testing”  Contraindications  Testing modalities  Including CTA  Test selection  Cases

Indications  Suspected CAD  Pre-operative  Pulmonary hypertension  DOE  Valvular heart disease  Viability  Risk stratification

Indications: Suspected CA

Bayes’ Theorem

Indications: Suspected CA

Indications: Suspected CA

Contraindications

Evaluation of Suspected CAD (symptomatic)  Treadmill ECG  Stress Echo  Exercise  Dobutamine  Myocardial perfusion (nuclear)  Exercise  Persantine  CTA  Coronary angiography (invasive)

Evaluation of Suspected CAD  Functional:  Treadmill ECG  Stress Echo  Myocardial perfusion  Anatomic  CTA  Coronary angiography

Treadmill ECG  Exercise: preferred if possible  Treadmill  Good for detecting ischemia and arrhythmia  Cheap  Readily available

Treadmill ECG

Stress Echo and Outcomes

Stress Echo

MPI and Outcomes

MPI

MPI

Test Performance  Stress echo:  Sensitivity = 85%  Specificity = 77%  Stress MPI:  Sensitivity = 87%  Specificity = 64%

Bayes’ Theorem  The probability of a patient having the disease after a test is performed depends on pretest probability and the test characteristics

Bayes’ Theorem

Bayes’ Theorem

Bayes’ Theorem

Bayes’ Theorem Use Clinical Judgment!

RWC Case #1  56 year old female with a history of hypertension, dyslipidemia, fibromyalgia and chronic L-sided upper chest pain who reports 3 months mid-chest burning with exertion.  What is her pre-test probability of obstructive CAD?

Bayes’ Theorem

RWC Case #1  Treadmill Test:  6:55 Bruce Protocol  chest burning at peak exercise  1mm horizontal ST depression

Invasive Coronary Angiography

Invasive Coronary Angiography

RWC Case #2  43 y.o. woman without CAD risk factors presents with 2 week history of sharp chest pain lasting 1-2 min  ECG is normal  What is the pre-test probability?

Bayes’ Theorem

RWC Case #2  Treadmill test:  8 min on Bruce protocol  Borderline ST depressions  Equivocal test  Stress thallium was (-) for ischemia

RWC Case #3  43 year old male smoker with h/o dyslipidemia presents to ED with 1-2 week history of chest pain with and without exertion  Ruled out for MI in ED, EKG normal  What is his pre-test probability of obstructive CAD?

Bayes’ Theorem

RWC Case #3  Same-day treadmill test  4:20 seconds Bruce Protocol (7.0 METs)  118 bpm (66% of MPHR)  Normal blood pressure response  Chest pain after 2 minutes  No ischemic ST-T changes were noted  Referred for CT angiogram

Coronary CT Angiography LAD LV RV

Invasive Coronary Angiography

RWC Case #3 Invasive Angiography Cardiac CT

PCI of the LAD

Coronary CT Angiography  Non-invasive diagnostic imaging test using CT technology and contrast to diagnose the presence and severity of coronary artery disease  Significant improvement in diagnostic accuracy because of increase in detector rows from 4 to 16 to 64  High negative predictive value (NPV)

Coronary CT Angiography  28 studies (>2,400 patients) evaluating the sensitivity and specificity coronary artery disease (>50% stenosis) in CTA when compared with coronary angiography  Sensitivity: 99%  Specificity: 89%  PPV: 93%  NPV: 100% Mowatt G., Heart 2008 94; 1386-1393 

Coronary CT Angiography  Indications:  Equivocal stress test  Symptomatic patients with an intermediate probability of obstructive CAD  Young patient prior to valve surgery  Anomalous coronary artery  Avoid when:  No symptoms  CKD (GFR<60)  Atrial fibrillation or frequent PAC’s/PVC’s  Pregnant  Dye hypersensitivity

Coronary CT Angiography  Experience at Kaiser RWC  64 slice CT scanner  First CTA in 2007  >200 CTA’s performed  Preparation:  Renal Function <30 days prior to scan  Hold Metformin 48 hours prior  Metoprolol 25mg the night before and 50mg morning of scan  Prior to Scan  18 gauge iv started in antecubital vein of L arm  +/- iv metoprolol at time of scan  SL NTG  90 cc of contrast

Coronary CT Angiography  >9,000 patients who underwent coronary CTA  Followed for 20 months  Endpoints  Major adverse cardiac events  Death  MI  Revascularization

Coronary CTA- Prognosis

Radiation Exposure  Experimental and epidemiologic evidence show strong link between low- dose ionizing radiation and solid cancers and leukemia  Medical uses of radiation are the largest source exposure to public  Measured in sieverts (Sv)  Unit of ionizing radiation absorbed  Attempts to reflect the biological effect rather than the physical aspects  Background radiation in one year (3mSv)

Radiation  Retrospective study of >950,000 patients enrolled in United Health Care  Utilization data were used to estimated:  cumulative effective dose  3 year study period NEJM 2009;361:849-57 

Radiation  Background Radiation: 3 mSv/year

Radiation

Radiation Exposure Shuman, W,Radiology 248;2:431-37 

RWC Case #4  76 year old male with known CAD with a history of NSTEMI in July 2009 -> stent placement to the LAD and LCx who reports:  3 months of non-exertional L shoulder and upper arm discomfort  What is his pre-test probability of obstructive CAD?

Bayes’ Theorem

RWC Case #4  Referred for treadmill EKG test  Bruce Protocol  6 minutes  L arm pain and diaphoresis  130/90 mmHg (rest)  96/70 mmHg at peak exercise  1 mm ST segment elevation in the inferior leads

Invasive Coronary Angiography

Safety of Stress Echo  Exercise > dipyridamole > DSE N=85,997 1/557 1/1,294 1/6,574

RWC Case #5  92 year old active female with a h/o CAD, s/p CABG x 3 in 1980 who lives alone presented to the ED with 12 hours of chest pressure. No improvement with sl ntg or asa.  Ruled out for MI in ED, EKG normal; cxr normal  What is her pre-test probability of obstructive CAD?

Bayes’ Theorem 90-99

RWC Case #5  Same-day treadmill test  9:30 seconds on modified Bruce Protocol (4.6 METs)  128 bpm (100% of MPHR)  Normal blood pressure response  Pt did not report cp or dyspnea with exercise  Non-specific st-t changes that did not meet criteria for ischemia

RWC Case #5  She presented to the RWC ED about two weeks later with recurrent chest pain and nausea  EKG showed changes consistent with acute posterior ST segment elevation MI  Heart Alert activated; patient taken urgently to RWC cath lab

Invasive Coronary Angiography

Invasive Coronary Angiography

Case Discussion  Why was this patient’s treadmill test negative?  Non-obstructive disease (true negative)  Obstructive disease (false negative)

Stress Testing in CABG patients  Exercise echo and coronary angiography performed in 182 CABG patients JACC 1995;25:1019-23 

Stress Testing in CABG Patients “The exercise ECG has a number of limitations after coronary bypass surgery. Resting ECG abnormalities are frequent, and if an imaging test is not incorporated in the study, more reliance must be placed on symptom status, hemodynamic response, and exercise capacity. Because of these considerations, together with the need to document the site of ischemia, stress imaging tests are more favored in this group, although there are insufficient data to justify recommending a particular frequency of testing.”  ACC/AHA 2002 Guideline Update for Exercise Testing

Plaque Rupture 86% Circulation. 1995 Aug 1;92(3):657-71.

Plaque Rupture