VELOCITY: Pre-PCI Hypothermia Increases Adverse Event Rate without Reducing Infarct Size

Summary

The Evaluation of Ultrafast Hypothermia Before Reperfusion in STEMI Patients trial [VELOCITY; NCT01655433] assessed the feasibility, safety, and efficacy of systemic hypothermia induced by peritoneal lavage in patients with STEMI prior to primary percutaneous intervention.

  • Interventional Techniques & Devices
  • Cardiology Clinical Trials
  • Myocardial Infarction
  • Interventional Techniques & Devices
  • Cardiology Clinical Trials
  • Myocardial Infarction
  • Cardiology

The Evaluation of Ultrafast Hypothermia Before Reperfusion in STEMI Patients trial [VELOCITY; NCT01655433], presented by Gregg W. Stone, MD, Columbia University Medical Center, New York, New York, USA, assessed the feasibility, safety, and efficacy of systemic hypothermia induced by peritoneal lavage in patients with STEMI prior to primary percutaneous intervention (PCI). Patients with symptoms of STEMI between 30 minutes and 6 hours before presentation and ST-segment elevation ≥ 2 mm in ≥ 2 continuous electrocardiography (ECG) leads who were intended for PCI were randomized to PCI (n = 26) or peritoneal hypothermia followed by PCI (n = 28). Cardiac magnetic resonance imaging (MRI) was performed at 3 to 5 days and 30 ± 7 days after PCI. Clinical follow-up took place at 30 days and 6 months after PCI.

An automated peritoneal lavage system was used to induce hypothermia to a core temperature of ≤ 34.9°C (target 32.5°C), maintained for 3 hours post PCI, after which the system initiated active rewarming and fluid drainage. The primary efficacy end point was infarct size assessed by cardiac MRI on day 3 to 5. The primary safety end point was the composite rate of death, reinfarction, ischemia-driven target vessel revascularization, major bleeding, sepsis, pneumonia, peritonitis, severe arrhythmia, or renal failure occurring within 30 ± 7 days.

PCI was performed in 25 of 26 patients randomized to PCI without hypothermia. Peritoneal access was attempted in 26 of 27 patients randomized to hypothermia followed by PCI. One of the 28 patients did not have peritoneal access or PCI and underwent surgery for aortic dissection. Peritoneal access was successful and hypothermia established in 26 of the 27 patients in whom access was attempted. PCI was performed in 27 patients.

The goal temperature of ≤ 34.9°C before PCI was achieved in 24 of 27 patients in the hypothermia group (88.9%) at a median 17.0 minutes after cooling onset. There were no significant differences in angiographic and ECG outcomes between the hypothermia and control groups. Cardiac MRI results at day 3 to 5 demonstrated no significant differences between the hypothermia and control groups in any parameters, including infarct size (P = .54; Table 1).

Table 1.

Cardiac MRI Results at Day 3 to 5

A prespecified subgroup analysis found no significant difference in infarct size at day 3 to 5 between patients in the hypothermia and control groups with left anterior descending (LAD) artery infarct (P = .68), non-LAD artery infarct (P = .11), and symptom onset to hospital arrival ≤ 3 hours (P = .17) or > 3 hours (P = .39).

The primary safety composite end point occurred in 21.4% of hypothermia patients vs 0.0% of controls (P = .02). There were no significant differences between the hypothermia and control groups in the major adverse cardiac event (MACE) and stent thrombosis rates.

Limitations of this study included the sample size, which was not powered for efficacy. The study was unblinded. Both nonanterior and anterior infarcts were included. The level of optimal cooling before PCI is unknown. Long-term follow-up was not available.

Controlled systemic hypothermia through automated peritoneal lavage may be rapidly established in patients with evolving STEMI undergoing primary PCI at the expense of a modest increase in door-to-balloon time, concluded Dr Stone. In this trial, peritoneal hypothermia was associated with an increased rate of adverse events without reducing infarct size.

View Summary