非虚血性低心機能症例に対するカルベジロールの逆リモデリング効果の予測因子としての心臓MRI遅延造影検査の有用性

Usefulness of Delayed Enhancement Cardiac MRI to Predict Reverse Remodeling by Carvedilol in Patients with Non-ischemic Cardiac Dysfunction

要旨　心臓MRIでのガドリニウム遅延造影(LGE)所見とカルベジロールの逆リモデリングとの関係を検討した．対象は冠動脈造影で有意狭窄病変がなく，左心室の収縮率(EF)が50%未満の56症例を対象とした．カルベジロール開始前にMRI検査を行い，開始前と開始後3カ月以後に超音波検査を施行した．カルベジロール開始前後で心拍数は80.9±19.6/minから69.1±11.0/minへと有意に低下した(p＜0.0001)．また，MRI所見からLGE陰性群，LGE低値群，LGE高値群の3群に分けて，カルベジロール開始後から前の拡張末期容量指標(EDVI)，収縮末期容積指標(ESVI)，EFを差し引いたΔEDVI，ΔESVI，ΔEFを比較した．ΔEDVI(ml/m²)は陰性群－31.0±32.7，低値群－24.0±21.7，高値群で－3.3±24.2，ΔESVI(ml/m²)は陰性群－31.0±27.5，低値群－30.7±18.8，高値群－7.0±20.1，ΔEF(%)は陰性群13.5±11.6，低値群18.3±9.6，高値群5.7±8.1と群間で有意な差を認めた．カルベジロール使用による逆リモデリングの効果はLGE所見の左室に占める割合によって異なっていた．

　We examined the relationship between late gadolinium enhancement(LGE)findings on cardiac MRI and the reverse remodeling effect of carvedilol. Fifty-six patients with left ventricular ejection fraction(EF)of less than 50% and no significant stenotic lesion on coronary angiography were studied. Cardiac MRI was conducted before carvedilol administration, and ultrasonography was conducted both before and 3 months after administration. Heart rate decreased significantly(p＜0.0001)from 80.9±19.6/min before administration to 69.1±11.0/min after administration. The patients were stratified into LGE-negative, low-LGE, and high-LGE groups from pre-treatment MRI findings. The change(post-treatment－pre-treatment values)in the end-diastole volume index(ΔEDVI), change in end-systole volume index(ΔESVI), and change in EF(ΔEF)were compared among these three groups. ΔEDVI(ml/m²)was －31.0±32.7 in the LGE-negative group, －24.0±21.7 in the low-LGE group and －3.3±24.2 in the high-LGE group. ΔESVI(ml/m²)was －31.0±27.5 in the LGE-negative group, －30.7±18.8 in the low-LGE group, and －7.0±20.1 in the high-LGE group. ΔEF(%)was 13.5±11.6 in the LGE-negative group, 18.3±9.6 in the low-LGE group, and 5.7±8.1 in the high-LGE group. Significant differences were observed between groups for all three parameters. The reverse remodeling effect as a result of carvedilol administration differed depending on the percentage of LGE findings in the left ventricle.