Coronary vascular dysfunction and prognosis in patients with chronic kidney disease.
OBJECTIVE
This study sought to evaluate whether impaired vasodilator function, an early manifestation of coronary artery disease, which precedes angiographic stenosis, accounts for increased risk among patients with moderate to severe renal dysfunction.


BACKGROUND
Patients with renal dysfunction are at increased risk of adverse cardiac outcomes, even in the absence of overt myocardial ischemia or infarction.


METHODS
We included 866 consecutive patients with moderate to severe renal dysfunction referred for rest and stress myocardial perfusion positron emission tomography and followed them for a median of 1.28 years (interquartile range: 0.64 to 2.34). Regional myocardial perfusion abnormalities were assessed by semiquantitative visual analysis of positron emission tomography images. Rest and stress myocardial blood flow were calculated using factor analysis and a 2-compartment kinetic model; they were also used to compute coronary flow reserve (stress/rest myocardial blood flow). The primary endpoint was cardiac death.


RESULTS
Overall, 3-year cardiac mortality was 16.2%. After adjusting for clinical risk, left ventricular ejection fraction, as well as the magnitude of scar and/or ischemia, coronary flow reserve below the median (<1.5) was associated with a 2.1-fold increase in the risk of cardiac death (95% confidence interval [CI]: 1.3 to 3.5, p = 0.004). Incorporation of coronary flow reserve into cardiac death risk assessment models resulted in an increase in the C-index from 0.75 to 0.77 (p = 0.05) and in a net reclassification improvement of 0.142 (95% CI: 0.076 to 0.219). Among patients at intermediate risk based on all data other than coronary flow reserve, the net reclassification improvement was 0.489 (95% CI: 0.192 to 0.836). Corresponding improvements in risk assessment for mortality from any cause were also demonstrated.


CONCLUSIONS
The presence of coronary vascular dysfunction in patients with moderate to severe renal dysfunction, as assessed by positron emission tomography, is a powerful, independent predictor of cardiac mortality and provides meaningful incremental risk stratification over conventional markers of clinical risk.
Cardiovascular Imaging Program, Brigham and Women's Hospital, Boston, MA 02115, USA.
Venkatesh L
VL
Murthy
Masanao
M
Naya
Courtney R
CR
Foster
Jon
J
Hainer
Mariya
M
Gaber
Sharmila
S
Dorbala
David M
DM
Charytan
Ron
R
Blankstein
Marcelo F
MF
Di Carli
D000368:Aged; D000369:Aged, 80 and over; D002316:Cardiotonic Agents / Q000627:therapeutic use; D002423:Cause of Death; D016009:Chi-Square Distribution; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005163:Factor Analysis, Statistical; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D015999:Multivariate Analysis; D055414:Myocardial Perfusion Imaging / Q000379:methods; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013318:Stroke Volume; D013997:Time Factors; D014664:Vasodilation; D014665:Vasodilator Agents / Q000627:therapeutic use; D016277:Ventricular Function, Left
D002316:Cardiotonic Agents; D014665:Vasodilator Agents