This is a terrific study, thank you for sharing. This graph shows us so elegantly how much we don’t know. Perhaps this is why we have such trouble showing benefit when we fix the epicardial stenosis…
It is consistent with what this substack has taught me- look deeply at the entrenched wisdom and magnitude of benefit, help patients to make decisions based on these.
Just like RITA, ORBITA, STICH, trials show much smaller than expected (if any?) benefit of revascularization. Why did i learn about these trials from this substack and not my academic mentors?
I work in an academic institution and continue to challenge staff and trainees with what I learn here.
Keep up the good work. You are reaching people. Thank you!
This was super interesting. Thank you. I rarely listen to a podcast twice, but that's my plan. I wonder if dysfunction in the regulation of the microcirculation might be the mechanism behind walk-through angina.
Amazing stuff. Is this the collateral circulation that I heard about through many years of running. Why didn't an athlete like Jim Fixx have a fatal result. Supposedly it is said that he had a ruptured plaque. I would like a comment from Dr Murthy on that. Thank you for your comments gentlemen.
The taped discussion would be more helpful if it included the concept of collateral circulation which most of us have been led to believe is the compensatory improvement of epicardial vessels that have some overlap to any area of myocardium and allowing a region typically served by an obstructed coronary to still be served adequately. Then certainly collateral vessels must have optimal microcirculation just as much as the microcirculation of a defective vessesl (or even moreso). Then are microcirculations separate but overlapping. Then the discussion could venture into the question of whether collateral resource actually overlaps by interdigitation of smaller arterioles that are in the downstream tributary supply of each epicardial larger arteriole ?.....or... is collateral shunting occurring at the level of some shared microcirc system ...or is it surmised that microvascular pathways are segregated all the way to capillaries from the source of each epicardial coronary?
Even as we recognize that there is a domain of microcirculation that must be healthy somewhat like there is an inflammasome in every tissue which must be stable...but the anatomic question remains: is there a unified microcirculation complete with extensive shunting...or mostly separate microcirculations responding downstream from their source epicardial vessels and arterioles... or some mix of the two.
Thank you for this very interesting discussion. Both you and Dr. Murthy did a great job in explaining the nature and importance of the myocardial microcirculation. Understanding the importance of the microcirculation certainly helps to explain a lot of the anomalies seen in respect to the correlation of clinically symptomatic disease with the degree of visible epicardial obstruction. Is there any information available on the actual pathophysiology of microvascular disease? Is there an actual reduction in the number of capillaries or perhaps a loss of responsiveness to vasodilatation in the capillary bed? Certainly information on the pathophysiology would be important in formulating treatment or preventive measures.
I am sure there is much more to this story than we have discovered. Thanks for the presentation.
This is a terrific study, thank you for sharing. This graph shows us so elegantly how much we don’t know. Perhaps this is why we have such trouble showing benefit when we fix the epicardial stenosis…
It is consistent with what this substack has taught me- look deeply at the entrenched wisdom and magnitude of benefit, help patients to make decisions based on these.
Just like RITA, ORBITA, STICH, trials show much smaller than expected (if any?) benefit of revascularization. Why did i learn about these trials from this substack and not my academic mentors?
I work in an academic institution and continue to challenge staff and trainees with what I learn here.
Keep up the good work. You are reaching people. Thank you!
This was super interesting. Thank you. I rarely listen to a podcast twice, but that's my plan. I wonder if dysfunction in the regulation of the microcirculation might be the mechanism behind walk-through angina.
Back to report that I did listen to the podcast again and took more away. If only I knew how to improve the health of the microcirculation.
Amazing stuff. Is this the collateral circulation that I heard about through many years of running. Why didn't an athlete like Jim Fixx have a fatal result. Supposedly it is said that he had a ruptured plaque. I would like a comment from Dr Murthy on that. Thank you for your comments gentlemen.
The taped discussion would be more helpful if it included the concept of collateral circulation which most of us have been led to believe is the compensatory improvement of epicardial vessels that have some overlap to any area of myocardium and allowing a region typically served by an obstructed coronary to still be served adequately. Then certainly collateral vessels must have optimal microcirculation just as much as the microcirculation of a defective vessesl (or even moreso). Then are microcirculations separate but overlapping. Then the discussion could venture into the question of whether collateral resource actually overlaps by interdigitation of smaller arterioles that are in the downstream tributary supply of each epicardial larger arteriole ?.....or... is collateral shunting occurring at the level of some shared microcirc system ...or is it surmised that microvascular pathways are segregated all the way to capillaries from the source of each epicardial coronary?
Even as we recognize that there is a domain of microcirculation that must be healthy somewhat like there is an inflammasome in every tissue which must be stable...but the anatomic question remains: is there a unified microcirculation complete with extensive shunting...or mostly separate microcirculations responding downstream from their source epicardial vessels and arterioles... or some mix of the two.
Thank you for this very interesting discussion. Both you and Dr. Murthy did a great job in explaining the nature and importance of the myocardial microcirculation. Understanding the importance of the microcirculation certainly helps to explain a lot of the anomalies seen in respect to the correlation of clinically symptomatic disease with the degree of visible epicardial obstruction. Is there any information available on the actual pathophysiology of microvascular disease? Is there an actual reduction in the number of capillaries or perhaps a loss of responsiveness to vasodilatation in the capillary bed? Certainly information on the pathophysiology would be important in formulating treatment or preventive measures.