New study shows inorganic nitrate's potential in protecting kidneys during coronary angiographic procedures
A groundbreaking clinical trial led by Queen Mary University of London, in collaboration with funding from Heart Research UK, has unveiled promising results regarding the use of inorganic nitrate in safeguarding patients against kidney damage during coronary angiographic procedures.
The study, published in the European Heart Journal, has revealed that a simple five-day course of once-daily inorganic nitrate significantly reduces the risk of a severe complication following a coronary angiogram, where the dye used can lead to kidney injury.
Contrast-induced nephropathy (CIN), also known as contrast-associated acute kidney injury, is a rare but serious complication that can occur following coronary angiography. This widely employed procedure allows healthcare professionals to assess the blood supply to the heart by injecting a special dye visible on x-rays. However, for certain high-risk patients, including older individuals and those with heart failure or chronic kidney disease, the incidence of CIN can be alarmingly high, reaching up to 55%.
The trial, spearheaded by Professor Amrita Ahluwalia at Queen Mary University of London, aimed to investigate whether ingesting inorganic nitrate could counteract the loss of nitric oxide in the body, a key mechanism underlying CIN. Nitric oxide plays a crucial role in protecting against oxidative stress, which is heightened during angiographic procedures.
Involving 640 patients undergoing angiography for non-ST-elevation Acute Coronary Syndrome at Barts Health NHS Trust, the trial administered once daily inorganic nitrate capsules (potassium nitrate) to 319 participants, while 321 received a placebo capsule (potassium chloride). The results were striking: patients receiving inorganic nitrate treatment exhibited significantly reduced rates of CIN (9.1% vs. 30.5% in the placebo group), along with lower rates of procedural myocardial infarction (2.7% vs. 12.5%) and improved renal function at three months. Moreover, they experienced reduced major adverse cardiac events at one year (9.1% vs. 18.1%) compared to those who received the placebo treatment.
Professor Amrita Ahluwalia Dean for Research, Faculty of Medicine and Dentistry at Queen Mary remarked on the significance of these findings, “The current gold-standard treatment for blocked coronary arteries is inserting a stent. To do this the cardiologist needs to be able to see where the artery is blocked and that is why it is necessary to use a dye to allow the artery to be clearly seen on the angiogram. This trial suggests that a simple 5-day regime of low-cost inorganic nitrate capsule eliminates the risk of what were, up till now, unavoidable damaging effects. We hope to confirm these findings in a large multi-centre trial in the near future, but the results of Nitrate-CIN give us hope.”
Kate Bratt-Farrar, Chief Executive at Heart Research UK, expressed delight in funding this transformative research, emphasizing its potential to enhance coronary angiogram protocols and reduce the risk of serious complications for patients.
The significance of this breakthrough cannot be overstated, especially considering that approximately 250,000 coronary angiograms are performed annually in the UK alone, with CIN accounting for a third of all hospital-acquired acute kidney injuries. With an associated mortality rate of 20.2% for those experiencing CIN, the implications of this research extend far beyond the confines of the laboratory.
The study holds the promise of revolutionizing current medical practices, potentially saving countless lives and improving patient outcomes across the UK and beyond.
Read the paper here: https://academic.oup.com/eurheartj/article-lookup/doi/10.1093/eurheartj/ehae100