Feasibility of semi-quantitative assessment of left ventricular contractile reserve in dilated cardiomyopathy.

BACKGROUND: We and others have shown previously that left ventricular (LV) contractile reserve assessed quantitatively by high-dose dobutamine stress-echocardiography (DSE) has prognostic implications in patients with dilated cardiomyopathy. PURPOSE: To assess the feasibility of semi-quantitative assessment of LV contractile reserve by differently skilled operators in patients with dilated cardiomyopathy. METHODS: High-dose DSE was performed in 63 consecutive patients, mean age 50 ± 10 years and ejection fraction (EF) 19 ± 8%. LVEF was calculated 1) using Simpson's biplane formula, and 2) semi-quantitatively (5% increments) by novice and experienced echocardiographers, and by a DSE expert. Patients were considered to have preserved LV contractile reserve if LVEF dobutamine-induced change was ≥5%. RESULTS: Twenty-seven (45.8%) patients died during the 5-year follow-up. The feasibility of the assessment was 89%, 94%, and 98% for novice and experienced readers and DSE expert, respectively. Kaplan-Meier analysis showed that LV contractile reserve assessed semi-quantitatively by DSE expert and experienced reader achieved the best prognostic separation (log rank 19.63 and 18.99, respectively, p < 0.001 for both), followed by quantitative assessment (log rank 9.76, p = 0.0018) and assessment by novice reader (log rank 8.76, p = 0.012). Areas under the curves were similar for quantitative and semi-quantitative assessment of LV contractile reserve. CONCLUSIONS: Our data indicate that semi-quantitative assessment of LV contractile reserve is feasible by differently skilled operators.

Semiquantitative histomorphometric analysis of myocardium following partial left ventriculectomy: 1-year follow-up.

BACKGROUND: Although partial left ventriculectomy (PLV) may have beneficial clinical effects in patients with dilated cardiomyopathy (DCM), there are no reports on effects of PLV on myocardial histology. The objective of this study was to assess histological properties of the LV myocardium 1 year following PLV as compared to histology at the time of the operation. METHODS: The study group consisted of 15 consecutive PLV survivors, predominantly male (13/15), aged 45+/-12 years. Surgical specimens and endomyocardial biopsies, taken 12 months postoperatively, were processed routinely and stained with Masson-trichrome. The following morphometric parameters were assessed semiquantitavely: (1) degree of hypertrophy and attenuation; (2) nuclear evidence of hypertrophy; (3) myofibrillar volume fraction; (4) degree of degenerative vacuolar changes; and (5) fibrosis volume fraction. RESULTS: Both New York Heart Association (NYHA) functional class and ejection fraction (EF) improved 12 months following surgery as compared to preoperative values (2.40+/-0.69 vs. 3.33+/-0.49, p<0.001, and 33.21+/-12.05% vs. 20.21+/-9.07%, p<0.001, respectively). Morphometric analysis demonstrated postoperative decrease in the degree of attenuation as compared to preoperative values (1.40+/-0.51 vs. 2.47+/-0.64, p<0.01), as well as a decrease in fibrosis volume fraction (2.07+/-0.80 vs. 2.67+/-0.49, p<0.001) and nuclear hypertrophy (1.27+/-0.46 vs. 1.67+/-0.62, p<0.05). On the other hand, postoperative increase in myofibrillar volume fraction (1.87+/-0.61 vs. 1.40+/-0.61, p<0.01) was noted. CONCLUSION: One year postoperatively, PLV has favourable effects on myocardial morphology that parallels improvement in the patient's functional status and LV systolic function.