The new NIRS-IVUS platform combines two complementary forms of information in a single intravascular imaging system. IVUS provides detailed information about the vessel lumen, plaque burden, vessel size and lesion morphology, while NIRS provides information about the lipid content of coronary plaque. This is particularly important because angiography primarily shows the lumen as a two-dimensional outline and does not reliably reveal the composition of the plaque.
A long-standing commitment to intravascular imaging
MSSH has a long history of adopting advanced intravascular imaging. The hospital has been using IVUS since 2006 and introduced Optical Coherence Tomography (OCT) in 2015. In 2017, the hospital procured an integrated OCT system, becoming the first centre in the Asia-Pacific region and India to have this system. Since then, the centre has performed more than 15,000 intravascular imaging procedures and has developed expertise as a Centre of Excellence and training centre for OCT.
The introduction of the NIRS-IVUS platform represents the next step in this continuing evolution. With nearly 100 procedures already completed, MSSH is building substantial clinical experience with the technology and integrating it into the management of patients undergoing complex coronary interventions.
Why NIRS is important
One of the distinctive strengths of NIRS is its ability to identify and quantify lipid within coronary plaque. A lipid-rich plaque can be clinically important because plaque composition is not apparent from angiography alone. NIRS generates quantitative information on lipid burden, including the lipid-core burden index (LCBI), helping the interventional cardiologist understand the nature of a lesion in addition to simply measuring the degree of narrowing.
This additional information can be particularly valuable in patients with complex or apparently intermediate lesions, acute coronary syndromes, diffuse atherosclerotic disease and lesions where plaque composition may influence procedural planning. The information can also support decisions regarding the intensity of lipid-lowering therapy and longer-term risk-factor management.
Importantly, NIRS-IVUS provides this information without the additional contrast requirement associated with OCT imaging. This can be useful when contrast exposure needs to be minimised, including in patients with renal dysfunction or during complex procedures where repeated imaging may otherwise increase contrast load.
Dr. S. Selvamani, Director of Interventional Cardiology, Meenakshi Super Speciality Hospital, said: “The significance of NIRS-IVUS is that it allows us to look beyond the angiographic appearance of a blockage. IVUS tells us about the structure of the vessel and the lesion, while NIRS adds information about the lipid content of the plaque. This combination gives us a more complete picture of coronary disease and can be particularly valuable when treating complex lesions. Having completed nearly 100 procedures with this technology, our team is developing considerable experience in using NIRS-IVUS to guide patient-specific treatment.”
Applications in complex coronary intervention
IVUS is particularly valuable in calcified coronary lesions, where calcium can make stent delivery and expansion more challenging. Intravascular imaging can help determine lesion morphology, vessel dimensions and the adequacy of lesion preparation, and can guide the use of plaque-modification techniques such as rotational or orbital atherectomy when clinically indicated.
During primary PCI for acute myocardial infarction, intravascular imaging can also provide additional information about the treated lesion and help assess the result of intervention. NIRS adds the ability to characterise lipid-rich plaque, which can provide information that conventional angiography cannot provide.
Another important advantage is the ability to perform intravascular imaging whenever clinically required during a procedure, without the limitations associated with repeated contrast-based imaging. The combination of structural information from IVUS and plaque-composition information from NIRS therefore supports more informed procedural planning and optimisation.
Comprehensive intravascular imaging capability
With the addition of NIRS-IVUS, MSSH now has access to the major intravascular coronary imaging modalities used in contemporary practice, including IVUS, OCT and NIRS-IVUS. These technologies are used alongside advanced plaque-modification techniques, including laser atherectomy, rotational atherectomy and orbital atherectomy, for selected complex coronary interventions.
The nearly 100 NIRS-IVUS procedures completed at MSSH mark an important milestone in the hospital’s continuing effort to bring advanced cardiovascular technology and specialised interventional expertise closer to patients in Madurai and the surrounding region.
Dr. R. Sivakumar, Head of Department and Director of Structural Interventions; Dr. N. Ganesan, Director of Academics; Dr. S. Selvamani, Director of Interventional Cardiology; Dr. M. Sampath Kumar, Lead in Paediatric Cardiology; Dr. Jeyapandian, Lead in Electrophysiology and Senior Interventional Cardiologist; and Dr. Ramesh Ardhanari, Medical Director and Mr. Dileep Bernard from the hospital were also present during the press meet.