Determinants of serious in-hospital complications in patients with Killip class 1/2 ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention.

Killip classification has been used to stratify the risk of patients with acute myocardial infarction (AMI). There were many reports that Killip class 3 or 4 is closely associated with poor clinical outcomes. In other words, Killip class 1 or 2 is associated with favorable clinical outcomes in patients with AMI, especially when patients received primary percutaneous coronary intervention (PCI). However, some patients with Killip class 1/2 suffer from serious in-hospital complications. This study aimed to identify factors associated with serious in-hospital complications of ST-segment elevation myocardial infarction (STEMI) in patients with Killip class 1/2. The primary endpoint was serious in-hospital complications defined as the composite of in-hospital death and mechanical complications. We included 809 patients with STEMI, and divided them into the non-complication group (n = 791) and the complication group (n = 18). In-hospital death was observed in 14 patients (1.7%), and mechanical complications were observed in 4 patients (0.5%). Final TIMI flow ≤ 2 was more frequently observed in the complication group (33.3%) than in the non-complication group (5.4%) (p < 0.001). Multivariate logistic regression analysis revealed that serious in-hospital complication was associated with final TIMI flow grade ≤ 2 (Odds ratio 6.040, 95% confidence interval 2.042-17.870, p = 0.001). In conclusion, serious in-hospital complication of STEMI was associated with insufficient final TIMI flow grade in patients with Killip class 1/2. If final TIMI flow grade is suboptimal after primary PCI, we may recognize the potential risk of serious complications even when patients presented as Killip class 1/2.

Association of peak C-reactive protein with long-term clinical outcomes in patients with ST-segment elevation myocardial infarction.

Peak C-reactive protein (CRP) levels following ST-segment elevation myocardial infarction (STEMI) are associated with left ventricular thrombus formation or cardiac rupture. However, the impact of peak CRP on long-term outcomes in patients with STEMI is not completely understood. The purpose of this retrospective study was to compare the long-term all-cause death after STEMI between patients with and without high peak CRP levels. We included 594 patients with STEMI, and divided them into the high CRP group (n = 119) and the low-moderate CRP group (n = 475) according to the quintile of peak CRP levels. The primary endpoint was all-cause death after the discharge of the index admission. The mean peak CRP level was 19.66 ± 5.14 mg/dL in the high CRP group, whereas that was 6.43 ± 3.86 mg/dL in the low-moderate CRP group (p < 0.001). During the median follow-up duration of 1045 days (Q1 284 days, Q3 1603 days), a total of 45 all-cause deaths were observed. The Kaplan-Meier curves showed that all-cause death was more frequently observed in the high CRP group than in the low-moderate CRP group (p = 0.002). The multivariate Cox hazard analysis revealed that high CRP was significantly associated with all-cause death (hazard ratio 2.325, 95% confidence interval 1.246-4.341, p = 0.008) after controlling for confounding factors. In conclusion, high peak CRP was significantly associated with all-cause death in patients with STEMI. Our results suggest that peak CRP may be useful to stratify patients with STEMI for the risk of future death.

Evaluation of Lower Limb Neuromuscular System Observability and Estimability of Muscle Activity.

In this work, we describe a method for estimating the muscle activity without drawing any assumptions regarding optimality principles in human motor control strategies; further, the method does not require any neural circuitry modeling which limits the neurophysiological terms and estimability of the method. We introduce the concept of system observability, which can reconstruct states from outputs and their derivatives based on system dynamics. Based on neuromuscular system observability, we estimate the muscle activity from joint torques and kinematics of multiple locomotive gaits, while considering the unknown neural inputs as system disturbances. Moreover, to quantify the robustness of the method, the degree of observability and parameter sensitivity are evaluated. Finally, the neurophysiological implications and generality of the method are addressed.