Patients with unstable angina have better survival outcomes when they undergo routine invasive coronary angiography a large Australian study reveals.
The findings have reignited an ongoing debate about how to best treat patients who present with the condition.
“It appears that there is a benefit to understanding the patient’s coronary anatomy very early after admission in terms of reducing risk of death at 12 months,” lead author of the study Associate Professor Vijaya Sundararajan from St Vincent’s Hospital in Melbourne told the limbic.
“And it doesn’t have to be done at the index presentation – we found that there is a window of two months – in that time period following the initial presentation there is a clear benefit to patients undergoing this invasive diagnostic procedure.”
The decade-long observational study found that of more than 33,000 patients admitted to hospitals in Victoria with a diagnosis of unstable angina 43% went on to receive angiography on admission and an additional 9% received it within the following 12 months.
Propensity score matching revealed that routine angiography was associated with a 52% decrease in 12-month mortality (hazard ratio, 0.48 [95% CI, 0.38 to 0.61]) compared to those who received diagnostic angiography alone.
However, patients who also received revascularisation in addition to an angiography gained no additional survival benefit, the study results showed.
Professor Sundarajan told the limbic that this finding was difficult to understand.
“It’s possible that the diagnostic test stratifies people enough that those who need angioplasty or PCI clearly go on to get one while those who don’t have obstructive coronary artery disease may have had other reasons for their symptoms which are best managed with medications.
Despite the findings from the trial, Professor Sundararajan said the level of evidence was not yet there to recommend the invasive procedure as a standard of care for people with unstable angina.
“The guidelines state very clearly that there isn’t enough information to support an invasive pathway … what we think is that it’s now up to guidelines committees in their next review to critique this study and ask where it belongs.”
In the meantime, Dr Sundararajan said the findings should give physicians considering angiography for their patients with unstable angina reassurance that the procedure is worthwhile.
But the authors of a linked editorial Dr Sanjit Jolly and Professor Devereaux from McMaster University in Canada remained cautious about the findings.
“Physicians often do not refer patients who are elderly or frail or have renal failure or cognitive problems; therefore, this inherent bias might create large differences in baseline risk,” they warned.
They maintain that a large randomised is needed to investigate the effects of a routine invasive strategy specifically in patients with unstable angina and a negative high sensitivity troponin measurement.