Intravascular imaging and physiology guided interventions in complex chronic diseases as kidney failure and diabetes mellitus

Abstract

Coronary artery disease (CAD) is the leading cause of death globally. There are a variety of risk factors for the development of CAD including diabetes mellitus (DM), hypertension, hyperlipidemia, smoking, sedentary lifestyle, genetic factors, and others. Together, they exert a significant role in the development of CAD, especially when these risk factors are combined. The burden of cardiovascular diseases (CVDs), secondary to chronic conditions like DM, obesity, hypertension and associated renal disease, is rapidly increasing worldwide, not only in developed countries, but also in low-and medium- income developing countries.

Coronary angiography (CA) is considered the gold standard test for the diagnosis of CAD. An accurate interpretation of CA is of paramount importance in decision-making by the Clinicians to treat patients with CAD. CA has the inherent limitation of being a two-dimensional X-Ray lumeno-gram of a complex three-dimensional vascular structure. Visual assessment of angiogram can lead to both inter- and intra-observer variability in the assessment of the severity and extent of the disease which can lead to differences in management strategies.

Catheterization cardiology has been revolutionized recently and today; modern catheterization laboratories globally are fully equipped with adjunctive technologies. These include Quantitative Coronary Angiography (QCA), Fractional Flow Reserve (FFR), Intra-Vascular Ultra-Sonography (IVUS) and Optical Coherence Tomography (OCT) to help the Clinicians to make a well-informed decision based on detailed anatomical and physiological assessments of a coronary artery rather than judgment based solely on visual assessment.

Despite the introduction of coronary physiology and intravascular imaging in very early cases of coronary intervention, practical use of these techniques in the catheterization laboratory did not begin until the late 1990s. A variety of reasons have been understood as hurdles during the initial adoption of these clinical tools in cardiac catheter laboratories. The technological and theoretical aspects were not well understood initially, and currently used well-matured pressure wires which were not readily available. Nevertheless, coronary physiology and intravascular imaging have established a vital role in decision making process during cardiac catheterization laboratory.

This doctoral thesis, via several previous high impact journal publications, emphasized and supported the role of intracoronary imaging and physiology, mineralocorticoids antagonism and infarct size reduction in various clinical settings. The thesis has highlighted that decision-making with the help of intracoronary imaging and physiology is safe, effective and the clinicians can safely defer the decisions of coronary interventions based on negative value or non-ischemic values (Fractional Flow Reserve, FFR>0.80) based on the physiology. It has also been established that these techniques are cost-effective as well. The presented thesis also highlights the utility and evidence behind these adjunctive techniques, supported by clinical cases and highlights the importance of these techniques to make a well-informed treatment decision.

The thesis for PhD by Publication has clearly demonstrated, and more so, emphasized the clinical utility of intra-coronary imaging and physiology in complex disease processes like diabetes mellitus and chronic kidney disease (CKD).