A recent article published in Times of India, Sunday 24 March 2019, headlined “Now Chembur Hospital Doc Says Goodbye to Stents, Blood Thinners, “Near Infrared Light Looks Inside Heart Arteries.” Is it true?
The Times article describes the case of three acute heart attack patients, two in their 20s and one in her 30s, all admitted with acute heart attack to a private Hospital in Chembur, a suburb of Mumbai. In all three cases, optical coherence tomography (OCT) imaging was used to determine that the patients had thrombi, not plaque rupture, and all three were treated with thrombolysis instead of a stent. “We are planning to conduct a research study looking at heart attacks among the young using OCT,” the hospital cardiologist, has quoted in the article as saying. “This could help develop better guidelines to prevent unnecessary stenting among the young.”
There was lot of criticism on this article on Twitter and the hospital owner had to tweet, “I agree the headlines could be misleading, but the content of the article is absolutely scientific. We fully stand by it. It was an article and hence the headline and content is not in our control.”
What is the mechanism of heart attack?
An atherosclerotic plaque that gets ruptured leading to formation of a thrombus on the surface of plaque causes heart attacks was the time-honed concept. Recent data suggests that thrombus formation happens in majority (70%) but not all. The rest 30% are due to a newly identified mechanism called “plaque erosion”. So we have two mechanisms for heart attack – plaque rupture and plaque erosion.
What is the best way to manage a heart attack?
Management of acute heart attack as per the latest guidelines is to perform an emergency angiography of heart vessels and if the vessel is occluded, to open it by implanting a stent. This strategy assumes that the underlying mechanism is a plaque rupture.
Now that we have identified another mechanism for heart attack – plaque erosion – do we need to adopt a different strategy?
Identifying plaque erosion is not possible by cath lab coronary angiography or CT coronary angiography. This can be detected by a technology – Optical Coherence Tomography – an expensive research tool as of now. How to manage patients with heart attack secondary to plaque erosion is not addressed till date by major scientific societies, as there are no studies on this topic.
What is Optical Coherence Tomography?
Optical coherence tomography (OCT) is a novel invasive imaging technique that produces high-resolution images from within heart vessels. Compared to this angiography views the heart vessels from outside. It can be expected that OCT imaging provides superior resolution.
What are the cost implications?
The cost of OCT machine is more than a one crore rupees and the cost of every catheter is nearly seventy five thousand rupees. The additional cost for performing an OCT examination per patient varies from 75000 to one lakh rupees that is beyond the reach of a common person.
Does this cost justify benefit?
As of now the data does not support the use of this technology for all patients. It may be reserved for certain scenarios where additional information is needed.
Can we avoid stents in heart attack?
It is important to recognize that angioplasty and stent implantation is the standard way for managing heart attack patients. Thrombolysis (managing with clot dissolving medicine) is an alternate way of managing where cath lab cannot be reached in the next 120 minutes.
Even for those patients who receive thrombolysis, it is important to get angiography and if required stent implantation within 24 hours. Beyond 24 hours managing by stent has to be done only for certain groups of patients and not all heart attack patients.
Managing heart attack by emergency angiography – angioplasty – stent is the best way to manage heart attack. OCT is useful in special scenarios and cannot be recommended for all heart attack cases considering the cost-benefit analysis.