Study Examines Use of Systolic Blood Pressure at Time of Primary PCI to Predict In-Hospital Mortality in Patients With STEMI
September 11, 2017—The Society for Cardiovascular and Angiographic Interventions (SCAI) announced the publication of a retrospective single-center study examining simple hemodynamic parameters obtained at the time of cardiac catheterization to predict in-hospital mortality after ST-elevation myocardial infarction (STEMI). The study was published by Michael Sola, et al in the Editor’s Choice article of the September 2017 issue of Catheterization and Cardiovascular Interventions(2017;90:389–395).
The investigators examined the prognostic utility of an index based on systolic blood pressure (SBP) and left-ventricular end-diastolic blood pressure (LVEDP) ratio measured at the time of emergency primary percutaneous coronary intervention (PPCI). Current 30-day mortality rates for patients with STEMI range from 2.5% to 10%, and 10.5% to 24% of those patients require mechanical hemodynamic support, noted SCAI.
The study evaluated adult patients (≥ 18 years of age) with STEMI undergoing PPCI from April 11, 2007 to December 12, 2011. The final study included 219 patients with a mean age of 60 ± 14 years. Patients’ LVEDP, SBP, and aortic diastolic blood pressure were measured after successful revascularization and compared to major mortality risk scores.
Study investigator George Stouffer III, MD, commented in the SCAI press release, “Our results are the first to demonstrate that the ratio of SBP/LVEDP when measured at the time of PPCI is a useful predictor of in-hospital mortality and 30-day mortality for patients experiencing STEMI. Invasive hemodynamic measurements at the time of PPCI have the theoretical advantage of better reflecting both left ventricular loading conditions and afterload than noninvasive assessments. Our results show that this simple index predicted mortality at a level consistent with more commonly used and more cumbersome prognostic indices, such as the Thrombolysis in Myocardial Infarction score, the Global Registry of Acute Coronary Events score, and Killip Class.”
As summarized by SCAI, the SBP/LVEDP ratio of ≤ 4 was associated with a likelihood ratio of 4.7 for in-hospital death, 5.8 for intra-aortic balloon pump (IABP) usage, and 5.9 for the combined IABP usage or in-hospital death.
Dr. Stouffer stated, “The performance characteristics of this ratio at high levels provide rapid and accurate identification of patients at the time of PPCI for STEMI who are at low risk for death or need for IABP.” A total of 20 (9.1%) patients died in-hospital and 34 (15.5%) required an IABP. The area under curve for SBP/LVEDP ratio for in-hospital mortality (0.69) was more predictive than LVEDP (0.61; P = .04) or pulse pressure (0.55; P = .02), but similar to the Shock Index and Modified Shock Index.
Investigator Michael Yeung, MD, commented, “SBP/LVEDP is a rapidly determined ratio that can provide important prognostic information at the time of PPCI. The pressure values are readily obtained during PPCI and identify a population at high risk for mortality. This presents an opportunity to identify patients who might benefit from more aggressive hemodynamic support while in the cardiac catheterization laboratory.”