Feasibility of cardiovascular magnetic resonance to detect oxygenation deficits in patients with multi-vessel coronary artery disease triggered by breathing maneuvers.
BACKGROUND
Hyperventilation with a subsequent breath-hold has been successfully used as a non-pharmacological vasoactive stimulus to induce changes in myocardial oxygenation. The purpose of this pilot study was to assess if this maneuver is feasible in patients with multi-vessel coronary artery disease (CAD), and if it is effective at detecting coronary artery stenosis > 50% determined by quantitative coronary angiography (QCA).


METHODS
Twenty-six patients with coronary artery stenosis (QCA > 50% diameter stenosis) underwent a contrast-free cardiovascular magnetic resonance (CMR) exam in the time interval between their primary coronary angiography and a subsequent percutaneous coronary intervention (PCI, n = 24) or coronary artery bypass (CABG, n = 2) revascularization procedure. The CMR exam involved standard function imaging, myocardial strain analysis, T2 mapping, native T1 mapping and oxygenation-sensitive CMR (OS-CMR) imaging. During OS-CMR, participants performed a paced hyperventilation for 60s followed by a breath-hold to induce a vasoactive stimulus. Ten healthy subjects underwent the CMR protocol as the control group.


RESULTS
All CAD patients completed the breathing maneuvers with an average breath-hold duration of 48 ± 23 s following hyperventilation and without any complications or adverse effects. In comparison to healthy subjects, CAD patients had a significantly attenuated global myocardial oxygenation response to both hyperventilation (- 9.6 ± 6.8% vs. -3.1 ± 6.5%, p = 0.012) and apnea (11.3 ± 6.1% vs. 2.1 ± 4.4%, p < 0.001). The breath-hold maneuver unmasked regional oxygenation differences in territories subtended by a stenotic coronary artery in comparison to remote territory within the same patient (0.5 ± 3.8 vs. 3.8 ± 5.3%, p = 0.011).


CONCLUSION
Breathing maneuvers in conjunction with OS-CMR are clinically feasible in CAD patients. Furthermore, OS-CMR demonstrates myocardial oxygenation abnormalities in regional myocardium related to CAD without the use of pharmacologic vasodilators or contrast agents. A larger trial appears warranted for a better understanding of its diagnostic utility.


TRIAL REGISTRATION
Clinical Trials Identifier: NCT02233634 , registered 8 September 2014.
['Fischer|Kady|K|', 'Yamaji|Kyohei|K|', 'Luescher|Silvia|S|', 'Ueki|Yasushi|Y|', 'Jung|Bernd|B|', 'von Tengg-Kobligk|Hendrik|H|', 'Windecker|Stephan|S|', 'Friedrich|Matthias G|MG|', 'Eberle|Balthasar|B|', 'Guensch|Dominik P|DP|']
D000368:Aged D015415:Biomarkers D062485:Breath Holding D016022:Case-Control Studies D017023:Coronary Angiography D003324:Coronary Artery Disease D023921:Coronary Stenosis D005240:Feasibility Studies D005260:Female D006454:Hemoglobins D006801:Humans D006985:Hyperventilation D019028:Magnetic Resonance Imaging, Cine D008297:Male D008875:Middle Aged D009206:Myocardium D010100:Oxygen D010865:Pilot Projects D011237:Predictive Value of Tests D056152:Respiratory Rate D014664:Vasodilation
Coronary artery disease Breathing maneuvers BOLD Hypercapnia Hypocapnia Oxygenation-sensitive cardiovascular magnetic resonance