Effects of caffeine on the detection of ischemia in patients undergoing adenosine stress cardiovascular magnetic resonance imaging

Abstract

BackgroundAdenosine stress cardiovascular magnetic resonance (CMR) can detect significant coronary artery stenoses with high diagnostic accuracy. Caffeine is a nonselective competitive inhibitor of adenosine2A-receptors, which might hamper the vasodilator effect of adenosine stress, potentially yielding false-negative results. Much controversy exists about the influence of caffeine on adenosine myocardial perfusion imaging. Our study sought to investigate the effects of caffeine on ischemia detection in patients with suspected or known coronary artery disease (CAD) undergoing adenosine stress CMR.MethodsThirty patients with evidence of myocardial ischemia on caffeine-naïve adenosine stress CMR were prospectively enrolled and underwent repeat adenosine stress CMR after intake of 200 mg caffeine. Both CMR exams were then compared for evaluation of ischemic burden.ResultsDespite intake of caffeine, no conversion of a positive to a negative stress study occurred on a per patient basis. Although we found significant lower ischemic burden in CMR exams with caffeine compared to caffeine-naïve CMR exams, absolute differences varied only slightly (1 segment based on a 16-segment model, 3 segments on a 60-segment model, and 1 ml in total ischemic myocardial volume, p < 0.001 each). Moreover, no relevant ischemia (≥2 segments in a 16-segment model) was missed by prior ingestion of caffeine.ConclusionsAlthough differences were small and no relevant myocardial ischemia had been missed, prior consumption of caffeine led to significant reduction of ischemic burden, and might lower the high diagnostic and prognostic value of adenosine stress CMR. Therefore, we suggest that patients should still refrain from caffeine prior adenosine stress CMR tests.

Impact of caffeine on myocardial perfusion reserve assessed by semiquantitative adenosine stress perfusion cardiovascular magnetic resonance

“…The cohort of this study was part of a previously reported trial, in which we found that caffeine consumption led to a slight reduction of perfusion defect size determined by visual assessment of adenosine stress CMR. The detailed design and main results of this previous trial have recently been published [4]. Briefly, between May 2014 and September 2015, 25 patients were enrolled in this substudy.…”

“…blinded to the patient's clinical status, caffeine status and other test results (e.g. coronary angiography) as previously described [4]. Stress and rest perfusion images were evaluated using qualitative and semiquantitative assessment by two experienced observers (A.S., S.G.).…”

“…Patients demonstrated a preserved LV ejection fraction of 64 ± 6%, and a normal LV end-diastolic volume index, Table 1. The median time period between the initial (caffeine-naïve) and the repeat (after defined caffeine intake) adenosine stress CMR was 12 (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) days. Hemodynamics (blood pressure, heart rate) during stress perfusion and rest perfusion were similar at both CMR exams, Table 3.…”

“…Previous studies have investigated the impact of caffeine on adenosine stress perfusion imaging using single photon emission computed tomography (SPECT), CMR or PET [6][7][8][9][10]. Despite overall inconsistent results about the impact of caffeine on adenosine stress exams, most groups found a reduced ischemic myocardial burden in some degree, if stress perfusion imaging was performed after caffeine consumption using the standard dose of adenosine (140 μg/kg/min) [4][5][6][7]10]. However, in the majority of studies, ischemic burden was defined rather by the size of perfusion defects and number of ischemic segments than by (semi-)quantitative assessment of myocardial perfusion.…”

“…Caffeine is a nonselective competitive inhibitor of adenosine2A-receptors, which might attenuate the vasodilator effect of adenosine, and increases sympathetic activity yielding to capillary de-recruitment, leading to decreased myocardial perfusion reserve [2,3]. However, studies investigating the effect of caffeine on adenosine-induced hyperemia reported inconsistent results: We and others have previously reported that caffeine consumption prior to adenosine stress perfusion CMR led to a reduction of ischemic burden on qualitative assessment [4][5][6][7]. Other groups, however, did not observe significant impact of caffeine on stress perfusion defect size [8,9].…”