Posts Tagged ‘Society of Thoracic Surgeons’

Coronary Reperfusion Therapies: CABG vs PCI – Mayo Clinic preprocedure Risk Score (MCRS) for Prediction of in-Hospital Mortality after CABG or PCI

Author and Curator: Larry H. Bernstein, MD, FCAP 


Curator: Aviva Lev-Ari, PhD, RN


Published on Mar 27, 2012

Mayo Clinic cardiologist Charanjit Rihal, M.D. discusses a recent study conducted by Mayo Clinic that focuses on predicting operator outcomes in coronary angioplasty procedures.

“We’ve been interested in prediction of outcomes after coronary angioplasty and stent procedures for some time,” says Dr. Rihal. “Almost ten years ago, we published a paper called ‘The Mayo Clinic Risk Score for Prediction of Adverse Events following Coronary Angioplasty and Stent Procedures’. We’ve since refined into the ‘New Mayo Clinic Risk Score’, which includes seven key variables that predict bad outcomes following PCI procedures.”

The study, which was presented at the 2012 ACC Annual Scientific Session & Expo, presents a novel application of the Mayo Clinic Risk Score to predict operator specific outcomes in coronary angioplasty procedures.

“We looked at the outcomes of over 8000 procedures performed by 21 Mayo Clinic interventional cardiologists as predicted by the Mayo Clinic Risk Score,” says Dr. Rihal. “On an individual basis, we were able to calculate the expected mortality and adverse event rate and compare that to the actual observed mortality and adverse event rate. We were able to show that in our clinical practice of PCI, this risk score was very useful as a performance measure.

In a pleasant surprise, the study also discovered an outlier whose outcomes for instances of adverse event rates were much better than expected. “We don’t know exactly why this operator has such good results,” remarks Dr. Rihal, “But that will be the next phase of this analysis. We can compare procedural, pre-procedural, and post procedural practices of this operator and see if there are things that are translatable to the rest of us.”


Singh M, Gersh BJ, Li S, Rumsfeld JS, Spertus JA, O’Brien SM, Suri RM, Peterson ED.
Circulation. 2008 Jan 22;117(3):356-62.  http://dx.doi.org/10.1161/CIRCULATIONAHA.107.711523     Epub 2008 Jan 2.  PMID: 18172033
BACKGROUND:  Current risk models predict in-hospital mortality after either coronary artery bypass graft surgery or percutaneous coronary interventions. The overlap of models suggests that the same variables can define the risks of alternative coronary reperfusion therapies. We sought  a preprocedure risk model that can predict in-hospital mortality after either percutaneous coronary intervention or coronary artery bypass graft surgery.
METHODS AND RESULTS:  We tested the ability of the recently validated, integer-based Mayo Clinic Risk Score (MCRS) for percutaneous coronary intervention, which is based solely on preprocedure variables:
  • age,
  • creatinine,
  • ejection fraction,
  • myocardial infarction < or = 24 hours,
  • shock,
  • congestive heart failure
  • peripheral vascular disease
to predict in-hospital mortality among 370,793 patients in the Society of Thoracic Surgeons  (STS) database undergoing isolated coronary artery bypass graft surgery from 2004 to 2006. The median age of the STS database patients was 66 years (quartiles 1 to 3, 57 to 74 years), with 37.2% of patients > or = 70 years old. The high prevalence of comorbid conditions included
  • diabetes mellitus (37.1%)
  • hypertension (80.5%)
  • peripheral vascular disease (15.3%)
  • renal disease (creatinine > or = 1.4 mg/dL; 11.8%).
A strong association existed between the MCRS and the observed mortality in the STS database. The in-hospital mortality ranged between 0.3% (95% confidence interval 0.3% to 0.4%) with a score of 0 on the MCRS and 33.8% (95% confidence interval 27.3% to 40.3%) with an MCRS score of 20 to 24. The discriminatory ability of the MCRS was moderate, as measured by the area under the receiver operating characteristic curve (C-statistic = 0.715 to 0.784 among various subgroups); performance was inferior to the STS model for most categories tested.
CONCLUSIONS:  This model is based on the 7 preprocedure risk variables listed above. However, it  may be useful for providing patients with individualized, evidence-based estimates of procedural risk as part of the informed consent process before percutaneous or surgical revascularization.
It appears to this reviewer that the model might provide a better AUC if it were reconstructed as follows:
  1. age
  2. estimated creatinine clearance (which has been improved substantially by the Mayo Clinic)
  3. EF
  4. AMI < 24 hrs
  5. Decompensated CHF or shock
  6. PVD, or carotid artery disease, or PAD
  7. MAP
Mean arterial pressure (MAP) Calculator: Systolic BP: mm Hg: Diastolic BP: mm Hg Background: Equation: MAP = [(2 x diastolic)+systolic] / 3      http://www.globalrph.com/map.htm
There is another question that This reviewer has about the approach to prediction of post-procedural survival from pre-procedural information.
  • Age falls into interval classes that would suffice for use as classification variables.
  • Creatinine is a measurement that is a continuous variable, but I  call attention to the fact that eGFR would be preferred, as physicians tend to look at the creatinine roughly in relationship to age, gender, and body size or BMI.
  • The laboratory contribution as powerful information is underutilized.
On the one hand, CHF is important, but how is the distinction made between
  • stable CHF and
  • decompensated CHF, or degrees in between?
This is where the amino-terminal pro b-type natriuretic perptide, or the BNP has been used in isolation, but not in a multivariate model such as described.  There is a difference between them, but whether the difference makes a difference is unproved.
The BNP, derived from the propeptide is made by the myocardium as a hormonal mediator of sodium retention.  The BNP is degraded by the vascular endothelium, so it’s half time of disappearance would not reflect renal dysfunction, which is not the case for the NT proBNP.  This observation has nothing to do with the medical use of BNP.
Related articles

Other related articles were published on this Open Access Online Scientific Journal, including:

Survivals Comparison of Coronary Artery Bypass Graft (CABG) and Percutaneous Coronary Intervention (PCI) / Coronary Angioplasty

Larry H Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN


Competition in the Ecosystem of Medical Devices in Cardiac and Vascular Repair: Heart Valves, Stents, Catheterization Tools and Kits for Open Heart and Minimally Invasive Surgery (MIS) (Aviva Lev-Ari)

Bioabsorbable Drug Coating Scaffolds, Stents and Dual Antiplatelet Therapy (Aviva Lev-Ari)

Vascular Repair: Stents and Biologically Active Implants (larryhbern)

Drug Eluting Stents: On MIT’s Edelman Lab’s Contributions to Vascular Biology and its Pioneering Research on DES (larryhbern)

Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents (Aviva Lev-Ari)

Survivals Comparison of Coronary Artery Bypass Graft (CABG) and Percutaneous Coronary Intervention (PCI) / Coronary Angioplasty (larryhbern)
Trans-apical Transcatheter Aortic Valve Replacement in a Patient with Severe and Complex Left Main Coronary Artery Disease (LMCAD) (larryhbern)
Transcatheter Aortic Valve Replacement (TAVR): Postdilatation to Reduce Paravalvular Regurgitation During TAVR with a Balloon-expandable Valve (larryhbern)

Svelte Medical Systems’ Drug-Eluting Stent: 0% Clinically-Driven Events Through 12-Months in First-In-Man Study (Aviva Lev-Ari)

Acute and Chronic Myocardial Infarction: Quantification of Myocardial Perfusion Viability – FDG-PET/MRI vs. MRI or PET alone (Justin Pearlman, Aviva Lev-Ari)

Biomaterials Technology: Models of Tissue Engineering for Reperfusion and Implantable Devices for Revascularization (larryhbern)
Revascularization: PCI, Prior History of PCI vs CABG (A Lev-Ari)
Accurate Identification and Treatment of Emergent Cardiac Events (larryhbern)
FDA Pending 510(k) for The Latest Cardiovascular Imaging Technology (A Lev-Ari)
The ACUITY-PCI score: Will it Replace Four Established Risk Scores — TIMI, GRACE, SYNTAX, and Clinical SYNTAX (A Lev-Ari)
CABG or PCI: Patients with Diabetes – CABG Rein Supreme (A Lev-Ari)
New Drug-Eluting Stent Works Well in STEMI (A Lev-Ari)

Three coronary artery bypass grafts, a LIMA to...

Three coronary artery bypass grafts, a LIMA to LAD and two saphenous vein grafts – one to the right coronary artery (RCA) system and one to the obtuse marginal (OM) system. (Photo credit: Wikipedia)

Forrester-classification for classification of...

Forrester-classification for classification of Congestive heart failure ; Forrester-Klassifikation zur Einteilung einer akuten Herzinsuffizienz (Photo credit: Wikipedia)

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