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

BACKGROUND: Adenosine 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. METHODS: Thirty 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. RESULTS: Despite 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. CONCLUSIONS: Although 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.

Advanced myocardial tissue characterisation by a multi-component CMR protocol in patients with rheumatoid arthritis.

OBJECTIVES: Rheumatoid arthritis (RA) patients are at increased risk of suffering from adverse cardiovascular events. Cardiovascular magnetic resonance (CMR) mapping techniques might be appropriate tools to complement late gadolinium enhancement (LGE) for the assessment of myocardial involvement. This study aimed to perform advanced myocardial tissue characterisation in RA patients by a multicomponent CMR protocol. METHODS: 22 RA patients were prospectively enrolled and underwent CMR, including LGE and T1/T2 mapping sequences; 20 volunteers served as controls. RESULTS: Mean LV-EF was 66%; prevalence of LGE was 18%. RA patients had increased native T1 (985 vs. 959 ms, p = 0.03), expanded extracellular volume (ECV) (27 vs. 25%, p = 0.02) and higher T2 values (52 vs. 49 ms, p < 0.001) compared to controls irrespective of the presence of LGE. T2 mapping showed the highest prevalence of values beyond the 95% percentile of controls. CONCLUSION: RA patients demonstrated higher T1, ECV and T2 values compared to controls, with most significant differences for T2. Since these results seem to be independent of the presence of LGE, advanced myocardial tissue characterisation including CMR mapping techniques in addition to LGE-CMR might be useful in the evaluation of myocardial involvement in RA patients. KEY POINTS: • RA patients had higher T1, ECV and T2 values compared to controls. • Most significant differences were observed for T2. • Our results seem to be independent of the presence of LGE. • Mapping might be useful in the evaluation of myocardial involvement in RA.

Evaluation of myocardial involvement in patients with connective tissue disorders: a multi-parametric cardiovascular magnetic resonance study.

BACKGROUND: Severe arrhythmias or heart failure may be surrogates of myocardial involvement in patients with connective tissue disorders (CTD). However, most patients present with unspecific symptoms, normal ECG, and preserved left ventricular ejection fraction (LV-EF). Therefore, timely diagnosis by an accurate technique is crucial. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) has proven value for the detection of focal processes, but due to the often diffuse character of fibrosis/inflammation in CTD patients, CMR mapping techniques might be of incremental value for the assessment of myocardial involvement. Purpose of this study was to evaluate a multi-parametric CMR protocol as a screening tool for myocardial involvement in CTD patients. METHODS: Forty CTD patients were prospectively enrolled and underwent CMR, twenty healthy volunteers served as control group. RESULTS: Mean LV-EF was 62 %; LGE prevalence was low (18 %). CTD patients had higher native T1 (1008 vs. 962 ms, p = 0.001), lower post contrast T1 (494 vs. 526 ms, p = 0.008), expanded extracellular volume (ECV) (28 vs. 25 %, p = 0.001), and higher T2 values (53 vs. 49 ms, p < 0.001) compared to controls. Among patients with values higher than the 95 % percentile of healthy controls, native T1 and T2 values seem to be the most promising discriminators. CONCLUSION: CTD patients showed higher T1, ECV, and T2 values compared to controls, with most significant differences for native T1 and T2, which seem to be independent of the presence of LGE. Our data suggest that CMR mapping techniques are of incremental value in the detection of myocardial involvement in CTD patients.

Dynamics of Concomitant Functional Mitral Regurgitation in Patients with Aortic Stenosis Undergoing TAVI.

BACKGROUND: The aim of this study was to investigate the echocardiographic features of functional mitral regurgitation (MR) in patients with aortic stenosis (AS) pre- and post-trans catheter aortic valve implantation (TAVI). METHODS: The study subjects consisted of 79 patients with severe AS, who underwent TAVI. The echocardiographic parameters related to MR severity prior to TAVI and the change in these parameters and MR severity within one month after implantation were retrospectively evaluated. RESULTS: The mean left ventricular ejection fraction (LVEF) was 53 ± 12%, and the mean MR severity was 1.2 ± 0.7. Among the baseline parameters, age (p = 0.019, r = 0.264), LV mass (p = 0.017, r = 0.269), deceleration time (DT) (p = 0.019, r = -0.266), left atrial diameter (p = 0.003, r = 0.325), were related to pre-procedure MR severity. After TAVI, the grade of MR (1.2 ± 0.7 vs. 0.8 ± 0.6, p < 0.001) and MR duration (43 ± 19% vs. 31 ± 23%, p < 0.001) were significantly decreased. The grade of pre-procedural MR (p < 0.001) was a predictor of residual MR after TAVI. However, there was not a significant change in the left ventricular echocardiographic parameters after TAVI [LVEF (53 ± 12 vs. 52 ± 11, p = 0.285), and LV mass (302 ± 84 vs. 306 ± 76 g, p = 0.495)]. CONCLUSIONS: In patients with severe AS, functional MR is related to age, LV mass, DT and left atrial diameter. TAVI improves MR in these patients, even before LV remodelling occurs.

Pocket-size imaging device: effectiveness for ward-based transthoracic studies.

AIMS: Pocket-size imaging devices (PSID) are now available; their potential role in a hospital environment has been investigated but still remains undefined. METHODS AND RESULTS: We evaluated the effectiveness of PSID in 92 patients referred for bedside transthoracic echocardiogram (TTE). Patients were included where there was a focused clinical question: quantification of left ventricular function (LVF); presence of regional wall motion abnormalities (RWMA); evidence of pericardial effusion, exclusion of significant valve pathology. Each patient underwent an echocardiography evaluation using PSID and TTE. In 83 patients [k = 90%, 95% CI (82.2-95.4)], it was possible to answer the clinical question by PSID examination alone. There was agreement between the findings of PSID and TTE in 86 cases [79%; k = 47%, 95% CI (12.8-82.0)], in three cases, the clinical question was not answered by both modalities. When the clinical question was focused on LVF, the agreement was excellent [k = 96%, 95% CI (95.3-97.9)], as was the agreement in the detection of RWMA [k = 94.57%, 95% CI (82.4-95.1)]. There was also good concordance in the detection of valve pathology and pericardial effusion. Using PSID, the reduction in the scanning and reporting time was 66%. The cost-effectiveness analysis produced very favourable results: with PSE, we obtained an overall cost saving per scan of 76%, compared with TTE. CONCLUSION: This study demonstrates that PSID can provide a valuable alternative to TTE in the presence of focused clinical questions and can provide an efficient way of delivering a ward-based transthoracic echo service.