No abstract

Background The prevalence of ischemia and its prediction of events are unclear in outpatient diabetic patients in the modern era of intensive medical management. We sought to identify the prevalence of ischemia, subsequent cardiac events, and impact of gender, stress type, and symptom status on these findings in a cohort of outpatient, stable diabetic patients referred for SPECT myocardial perfusion imaging (MPI). Methods and Results The study cohort included 575 consecutive diabetic outpatients who underwent quantitative, gated-SPECT MPI. Clinical information, stress MPI variables, and cardiac events were prospectively collected and analyzed. The study population was at intermediate risk of coronary artery disease (CAD) or had known CAD (40.3%); 29% were asymptomatic at the time of stress testing. Scintigraphic ischemia and significant (≥10%) left ventricular (LV) ischemia were present in 126 (21.9%) and 29 (5.0%), respectively, and <1% had early revascularization. The risk of ischemia was increased >2-fold by male gender (p<0.001) but was not impacted by pharmacologic stress (p=0.15) or presence of symptoms (p=0.89). Over median 4.4 years follow-up, the rate of cardiac death/nonfatal myocardial infarction (MI) was moderate at 2.6%/year (cardiac death 0.8%/year) in the total cohort but was 5.7%/year in those with ischemia (p<0.001). Pharmacologic stress predicted a higher cardiac event rate (p<0.001) but symptoms did not (p=0.55). Conclusions This stable outpatient diabetic SPECT referral cohort had low rates of significant ischemia and early revascularization; an initially-low initial cardiac event rate increased after 2 years. Independent predictors of cardiac death/nonfatal MI were known CAD, pharmacologic stress, and MPI ischemia. Nearly one-third of those with events had a normal MPI, indicating a need for improved risk stratification.

Doppler assessment of PCWP was neither sensitive nor specific enough to be clinically useful in anesthetized patients with mechanical ventilation. The fixed curve pattern of the interatrial septum was the best predictor of raised PCWP.