Safety and Feasibility Using a Fluid-Filled Wire to Avoid Hydrostatic Errors in Physiological Intracoronary Measurements.

Background: Using a fluid-filled wire with a pressure sensor outside the patient compared to a conventional pressure wire may avoid the systematic error introduced by the hydrostatic pressure within the coronary circulation. Aims: To assess the safety and effectiveness of the novel fluid-filled wire, Wirecath (Cavis Technologies, Uppsala, Sweden), as well as its ability to avoid the hydrostatic pressure error. Methods and Results: The Wirecath pressure wire was used in 45 eligible patients who underwent invasive coronary angiography and had a clinical indication for invasive coronary pressure measurement at Sahlgrenska University Hospital, Gothenburg, Sweden. In 29 patients, a simultaneous measurement was performed with a conventional coronary pressure wire (PressureWire X, Abbott Medical, Plymouth, MN, USA), and in 19 patients, the vertical height difference between the tip of the guide catheter and the wire measure point was measured in a 90-degree lateral angiographic projection. No adverse events caused by the pressure wires were reported. The mean Pd/Pa and mean FFR using the fluid-filled wire and the sensor-tipped wire differed significantly; however, after correcting for the hydrostatic effect, the sensor-tipped wire pressure correlated well with the fluid-filled wire pressure (R = 0.74 vs. R = 0.89 at rest and R = 0.89 vs. R = 0.98 at hyperemia). Conclusion: Hydrostatic errors in physiologic measurements can be avoided by using the fluid-filled Wirecath wire, which was safe to use in the present study. This trial is registered with NCT04776577 and NCT04802681.

Ischemic preconditioning affects phosphosites and accentuates myocardial stunning while reducing infarction size in rats.

Background and aims: Ischemic preconditioning (IPC), i.e., brief periods of ischemia, protect the heart from subsequent prolonged ischemic injury, and reduces infarction size. Myocardial stunning refers to transient loss of contractility in the heart after myocardial ischemia that recovers without permanent damage. The relationship between IPC and myocardial stunning remains incompletely understood. This study aimed primarily to examine the effects of IPC on the relationship between ischemia duration, stunning, and infarct size in an ischemia-reperfusion injury model. Secondarily, this study aimed to examine to which extent the phosphoproteomic changes induced by IPC relate to myocardial contractile function. Methods and results: Rats were subjected to different durations of left anterior descending artery (LAD) occlusion, with or without preceding IPC. Echocardiograms were acquired to assess cardiac contraction in the affected myocardial segment. Infarction size was evaluated using triphenyl tetrazolium chloride staining. Phosphoproteomic analysis was performed in heart tissue from preconditioned and non-preconditioned animals. In contrast to rats without IPC, reversible akinesia was observed in a majority of the rats that were subjected to IPC and subsequently exposed to ischemia of 13.5 or 15 min of ischemia. Phosphoproteomic analysis revealed significant differential regulation of 786 phosphopeptides between IPC and non-IPC groups, with significant associations with the sarcomere, Z-disc, and actin binding. Conclusion: IPC induces changes in phosphosites of proteins involved in myocardial contraction; and both accentuates post-ischemic myocardial stunning and reduces infarct size.