The reliability and feasibility of non-contrast adenosine stress cardiovascular magnetic resonance T1 mapping in patients on haemodialysis

Abstract

Background Identifying coronary artery disease (CAD) in patients with end-stage renal disease (ESRD) is challenging. Adenosine stress native T1 mapping with cardiovascular magnetic resonance (CMR) may accurately detect obstructive CAD and microvascular dysfunction in the general population. This study assessed the feasibility and reliability of adenosine stress native T1 mapping in patients on haemodialysis. Methods The feasibility of undertaking rest and adenosine stress native T1 mapping using the single-shot Modified Look-Locker inversion recovery (MOLLI) sequence was assessed in 58 patients on maintenance haemodialysis using 3 T CMR. Ten patients underwent repeat stress CMR within 2 weeks for assessment of test-retest reliability of native T1, stress T1 and delta T1 (ΔT1). Interrater and intrarater agreement were assessed in 10 patients. Exploratory analyses were undertaken to assess associations between clinical variables and native T1 values in 51 patients on haemodialysis. Results Mean age of participants was 55 ± 15 years, 46 (79%) were male, and median dialysis vintage was 21 (8; 48) months. All patients completed the scan without complications. Mean native T1 rest, stress and ΔT1 were 1261 ± 57 ms, 1297 ± 50 ms and 2.9 ± 2.5%, respectively. Interrater and intrarater agreement of rest T1, stress T1 and ΔT1 were excellent, with intraclass correlation coefficients (ICC) > 0.9 for all. Test-retest reliability of rest and stress native T1 were excellent or good (CoV 1.2 and 1.5%; ICC, 0.79 and 0.69, respectively). Test-retest reliability of ΔT1 was moderate to poor (CoV 27.4%, ICC 0.55). On multivariate analysis, CAD, diabetes mellitus and resting native T1 time were independent determinants of ΔT1 (β = − 0.275, p = 0.019; β = − 0.297, p = 0.013; β = − 0.455; p < 0.001, respectively). Conclusions Rest and adenosine stress native T1 mapping is feasible and well-tolerated amongst patients with ESRD on haemodialysis. Although rater agreement of the technique is excellent, test-retest reliability of ΔT1 is moderate to poor. Prospective studies should evaluate the relationship between this technique and established methods of CAD assessment and association with outcomes.

Myocardial blood flow is the dominant factor influencing cardiac magnetic resonance adenosine stress T2

“…We note that, while our resting T1 values are in line with those from other studies done on a 3 T system, 26,62 our changes in T1 from rest to stress (1.3% at the 4× adenosine dose, Table 1) are lower than what others have reported (2.8‐6.2%) 26,29,49 . Similarly, when using a conversion factor derived from Nickander et al, where a 34.4% change in MBV corresponded to a 6.2% change in T1, 29 our measured T1 values equate to an MBV increase of 7.31% at the 4× adenosine dose (Table 6), whereas other studies using systemic adenosine infusion reported increases of 30‐34% 29,52 .…”

“…It is interesting to note that in humans adenosine stress increases HR, 29,48–50 but pre‐clinically some studies report a decrease 8,51 similar to ours (Supporting Figure 2D,E), while others describe an increase 5,50,52 . This difference is not species specific, but instead may be caused by the anesthesia: studies using injectable anesthetics describe increased HR, while studies using inhaled anesthesia report a decrease in HR.…”

Ferumoxytol‐enhanced magnetic resonance T1 reactivity for depiction of myocardial hypoperfusion

“…A recent study at 3.0 T in patients on hemodialysis reported a mean native T1 reactivity of 3.01% in regions with normal wall motion and 1.6% in hypokinetic regions (MOLLI; adenosine: 140-210 μg/kg/min, 3 min). 41 The results in the latter study are descriptive, and the presence of advanced kidney disease in this patient population limits direct comparison of the native T1 reactivity, which may be affected by underlying microvascular dysfunction. However, the results support the use of wall motion to distinguish between normal and pathologic myocardial tissue and demonstrate applicability at a comparable magnet strength used in our study.…”

Stress CMR in Known or Suspected CAD: Diagnostic and Prognostic Role

“…Advantages of both native mapping and feature tracking could relate to the possibility of achieving a sensitive, noninvasive, quantitative measure of myocardial ischemia and tissue alterations, even without the need for contrast agents, which is desirable due to increasing age and frequent concomitant renal disease in CAD patients. Poli et al have tested the feasibility and reliability of noncontrast adenosine S-CMR T1 mapping in 58 patients under haemodialysis treatment and proved excellent test-retest reliability of rest and stress native T1 [ 80 ].…”