Given the task definition and input, reply with output. Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Context: Chronic atrial fibrillation (AF) is characterized by a remodeling process which involves the development of fibrosis. Since angiotensin II has been suspected to be involved in this process, the aim of our study was to investigate a possible influence of an ACE-I therapy in patients with chronic AF regarding the occurrence of left atrial structural remodeling.', 'Atrial tissue samples were obtained from patients with lone chronic AF or sinus rhythm (SR). Collagen I, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) protein expression were measured by quantitative Western Blotting techniques and calculated as mean +/- SEM. Histological tissue samples were used for calculating microvessel density (microvessel/mm(2) +/- SEM).', 'In AF, the collagen amount was higher (1.78 +/- 0.21; p = 0.01) vs. SR (0.37 +/- 0.07) accompanied by declining microcapillary density (AF: 145 +/- 13 vs. SR: 202 +/- 9; p = 0.01). Additionally, a negative correlation (p = 0.01) between collagen content and microcapillary density was observed. To investigate the influence of an ACE-I therapy on this remodeling process, patient groups were divided into AF and SR both with or without ACE-I. Interestingly, there was a significantly lower expression of collagen I in AF with ACE-I (1.04 +/- 0.26) vs. AF without ACE-I treatment (2.07 +/- 0.24, p = 0.02). The microcapillaries were not diminished in AF with ACE-I (180 +/- 15) vs. SR with ACE-I (196 +/- 9), but there was a significant rarification in AF without ACE-I (123 +/- 18; p = 0.03). The expression of VEGF and bFGF did not reveal any significant differences.
Answer: In patients undergoing ACE-I treatment: atrial structural remodeling was attenuated and the loss of atrial microcapillaries was prevented.
Does aCE-inhibitor treatment attenuate atrial structural remodeling in patients with lone chronic atrial fibrillation?