Related Experiment Video
Updated: Jul 5, 2025
Evaluation of Coronary Flow Reserve After Myocardial Ischemia Reperfusion in Rats
Published on: June 28, 2019
Coronary Sinus Narrowing Improves Coronary Microcirculation Function in Patients With Refractory Angina: A
Matteo Tebaldi1, Gianluca Campo2, Fabrizio Ugo3
1Cardiology Unit, Ospedale degli Infermi, Faenza (RA), Italy (M.T.).
Insights
Coronary sinus narrowing via reducer implantation significantly improved coronary microcirculation and reduced angina symptoms in patients with refractory angina. This intervention enhances microvascular function, offering new therapeutic insights.
Area of Science:
- Cardiology
- Vascular Biology
- Medical Devices
Background:
- Mechanisms of clinical benefits from coronary sinus narrowing are not fully understood.
- Investigating the impact of coronary sinus narrowing on coronary microcirculatory function.
Purpose of the Study:
- To evaluate the effect of coronary sinus narrowing on coronary microcirculatory function indexes.
- To assess changes in microcirculatory resistance, coronary flow reserve, and resistive resistance ratio.
Main Methods:
- Invasive physiological assessments in patients with refractory angina before and 4 months after coronary sinus reducer implantation.
- Primary outcome: change in index of microcirculatory resistance (IMR).
- Secondary outcomes: changes in coronary flow reserve (CFR) and resistive resistance ratio (RRR).
Main Results:
- IMR significantly decreased post-procedure (33.35±19.88 to 15.42±11.36, P<0.001).
- 71.4% of patients showed a significant IMR reduction; abnormal IMR decreased from 57% to 19%.
- Coronary flow reserve and resistive resistance ratio improved; angina symptoms (CCS class, SAQ score) also improved.
Conclusions:
- Coronary sinus reduction implantation significantly improves coronary microcirculatory function parameters.
- Findings suggest potential for treating coronary microvascular dysfunction and improving angina.
- The study provides insights into the benefits of coronary sinus narrowing for angina relief.
Background:
The underlying mechanisms responsible for the clinical benefits following coronary sinus narrowing and pressure elevation remain unclear. The present study aims to investigate whether coronary sinus narrowing improves the indexes of coronary microcirculatory function.
Methods:
Patients with refractory angina who had a clinical indication for reducer implantation underwent invasive physiological assessments before and 4 months after the procedure. The primary outcome was the change in the values of the index of microcirculatory resistance. Secondary end points included changes in coronary flow reserve and the resistive resistance ratio values. Angina status was assessed with the Canadian Cardiology Society class and the Seattle Angina Questionnaire.
Results:
Twenty-four patients with a history of obstructive coronary artery disease and prior coronary revascularization (surgical and percutaneous) treated with reducer implantation were enrolled, and 21 of them (87%) underwent repeated invasive coronary physiological assessment after 4 months. The index of microcirculatory resistance values decreased from 33.35±19.88 at baseline to 15.42±11.36 at 4-month follow-up (P<0.001; mean difference, -17.90 [95% CI, -26.16 to -9.64]). A significant (≥20% from baseline) reduction of the index of microcirculatory resistance was observed in 15 (71.4% [95% CI, 47.8%-88.7%]) patients. The number of patients with abnormal index of microcirculatory resistance (≥25) decreased from 12 (57%) to 4 (19%; P=0.016). Coronary flow reserve increased from 2.46±1.52 to 4.20±2.52 (mean difference, 1.73 [95% CI, 0.51-2.96]). Similar findings were observed for resistive resistance ratio values. Overall, 16 patients (76.1%) had an improvement of 1 Canadian Cardiology Society class. Seattle Angina Questionnaire summary score increase of around 3 points (3.01 [95% CI, 1.39-4.61]).
Conclusions:
Coronary sinus reduction implantation is associated with a significant improvement in the parameters of coronary microcirculatory function. These findings provide insights into the improvement of angina symptoms and may have implications for the treatment of coronary microvascular dysfunction.
Registration:
URL: https://www.clinicaltrials.gov; Unique identifier: NCT05174572.
More Related Videos
Related Concept Videos
01:25Antianginal Drugs: Calcium Channel Blockers and Ranolazine
CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This...
01:21Coronary Circulation
Coronary circulation begins at the base of the aorta, where two main arteries arise—the left and right coronary arteries. These arteries encircle the heart in the coronary sulcus and supply the...
01:16Antianginal Drugs: Nitrates and β-Blockers
Organic nitrates, such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow....
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System