NEW YORK (Reuters Health) – Outcomes following out-of-hospital cardiac arrest (OHCA) associated with ventricular tachycardia (VT) or pulseless ventricular fibrillation (VF) have been improving as the use of coronary angiography and percutaneous coronary intervention (PCI) has increased, according to a new study.

“Coronary artery disease is an underlying issue in the majority of VT/VF OHCA, so the growing use of coronary angiography tests and percutaneous coronary intervention procedures to open those blood vessels should have a positive impact on outcomes in appropriate patients,” Dr. Nish Patel of the University of Miami Miller School of Medicine in Florida told Reuters Health by email.

Dr. Patel and colleagues, whose findings appeared online September 14 in JAMA Cardiology, examined data on more than 400,000 patients hospitalized after VT/VF OHCA between 2000 and 2012.

As the researcher pointed out, “Our study found that 143,607 patients (35.2% of the total) underwent coronary angiography. However, the rate of coronary angiography increased from 27.2% in 2000 to 43.9% in 2012, while the PCI rate rose from 9.5% in 2000 to 24.1% in 2012.”

“At the same time,” he added, “survival to discharge in the overall patient population rose from 46.9% to 60.1%.”

For patients with ST-segment elevation (STE), survival increased from 59.2% to 74.3%, while and for those without STE, it went from 43.3% to 56.8%.

“Even though this is one of the largest studies to find a change in practice over time with regard to post-cardiac arrest angiography, several smaller studies have found similar trends,” the researchers note.

They also point out that, “Although there is a strong correlation with early coronary angiography after OHCA and improved outcomes, causation has yet to be proven.”

Dr. Patel concluded: “More studies are needed to determine if there is a link between these two trends, but in treating cardiac arrests, we appear to be on the right track.”

Commenting on the findings by email, Dr. Joaquin E. Cigarroa of Oregon Health & Science University in Portland told Reuters Health, “There is an association between coronary artery disease and out-of-hospital cardiac arrest which is clear in patients having a ST-segment elevation and suggested in patients without ST-segment elevation.”

“As such,” he added, “the ACC/AHA guidelines have evolved and, as per this study, are impacting the delivery of care with more patients receiving guideline-directed care. For the group of patients without ST-segment elevation, there are many unmeasured confounders that impact the likelihood of performing angiography and PCI, which may impact the results.”

Dr. Cigarroa, who is director of Cardiac Catheterization Labs, added that, “The findings of improved outcomes in patients presenting to larger urban hospitals underscores the importance of ‘cardiac arrest’ centers which have multidisciplinary systems including first responders to provide timely and appropriate care, as evidenced in prior studies in Europe.”

“This paper,” he concluded, “continues to extend the data supporting the use of angiography and PCI in selected patients presenting with OHCA” but as the researchers concede, “does not present definitive proof of cause and effect.”