Results
Cohort characteristics
The 34 patients with a diagnosis of CF included in the study were 17
girls and 17 boys with a mean age of 9.94±4.97 years, while of the 37
healthy volunteers, whose mean age was 9.85±4.33; 18 were female and 19
male. No significant differences between the two groups were detected
with regard to sex, age or weight (p>0.05). Testing for
gene mutation was positive in 19 (55.8%) and the sweat test was
positive in 30 (88.2%), with a mean score of 96.70±24.63 for the
latter. Gastrointestinal and pulmonary involvement was present in 30
(88.2%) and 23 (94.1%) patients, respectively. In 16 (64%) of the 25
patients with a pulmonary involvement determined on the CT-scan,
bronchiectasis was present. Of the CF patients, 4 (11.7%) had a history
of more than 10 in-patient hospital admissions for pulmonary infection;
the total number of such admissions was 5-10 in 10 (29.4%) and was less
than 5 in 15 (44.1%) patients. Colonization by Pseudomonas
aeruginosa was detected in 13 (38.2%) and that by Staphylococcus
aureus in 11 (32.3%). Of 19 patients who were subjected to respiratory
function testing, 13 (68.4%) showed an abnormal result; the remaining 6
(31.6%) were unremarkable in this regard.
Echocardiographic
Findings
M-mode and Doppler echocardiography results are summarized in Table 1.
While no difference could be detected between the patients and volunteer
groups with regard to LV measurements IVSd, IVSs, LVPWd, LVPWs, EF and
FS, there as a significant difference between them in LVDd and LVDs
measurements. Pulmonary artery systolic pressure (PAPs) was
significantly higher in the CF group compared to the controls
(32.50±4.09 and 28.96±2.82 mmHg, respectively; p<0.001).
Diastolic pulmonary artery pressure (PAPd) was 10.57±3.68 mmHg in the
patients and 9.00±2.08 mmHg in the control patients, with no
statistically significant difference detected. Similarly, no
statistically significant difference could be evidenced between the two
groups in the Doppler echocardiography parameters E-wave, A-wave, E/A
ratio and E/e’ ratio.
Color TDI results are summarized in Table 2. Color TDI measurement of LV
parameters also evidenced some systolic and diastolic dysfunction. When
compared to the controls by TDI, CF patients had shorter TST (343.7±37.5
ms vs. 367.8±38.6 ms respectively, p=0.009), EF (260.7±32.8 ms vs.
288±38.7 ms, p=0.002) and increased MPI (0.32±0.04 vs. 0.28±0.05,
p=0.001). Interventricular septal TST was reduced in CF patients
(341.1±38.6 ms vs. 361.1±3.2 ms in controls, p=0.027), ET was relatively
shortened (256.9±35 ms vs. 282.2±33.2 ms, p=0.002), IVRT lengthened
(47.6±5.8 ms vs. 44.4±5.3 ms, p=0.017) and MPI was increased (0.33±0.04
vs. 0.28±0.03, p=0.000).
Speckle Tracking
Echocardiography
LV longitudinal myocardial strain measurements indicated the following
reductions in segmental circumferential myocardial strain compared to
the control group: apical septal (-20.0±4.8 vs. -23.4±5.8, p=0.015),
apex (-20.0±4.8 vs. -23.4±5.8, p=0.003), AC3 chamber mid inferolateral
(-18.7±4.1 vs. -22.2±5.6, p=0.004), basal anteroseptal (-17.8±3.9 vs.
-21.4±5.7, p=0.004), mid inferior (-18.7±4.1 vs. -21.5±6.2, p=0.044),
apical inferior (-19.9±4.3 vs. -22.2±4.4, p=0.027), mid anterior
(-18.8±3.9 vs. -21.7±5.9, p=0.025). Global strain and total global
strain values did not appear to be different (Table 3). Circumferential
myocardial strain measurements of the LV wall showed significant
reductions in CF patients compared to controls in the basal inferior
(-17.9±7.2 vs. -21.2±6, p=0.049), mid inferior (-17.8±7 vs. -23.9±6.6,
p=0.001) and apical anterior (-21.6±6.6 vs. -27.5±5.2,
p<0.001) segments. No difference was observed between global
strain and total global strain values (Table 4). Longitudinal strain
rate measurements of CF patients by segment, compared to the controls by
segment, were as follows: in A4C mid anterolateral (-1.5±0.3 vs.
-2.0±0.5, p=0.001), in A3C basal inferolateral (-1.6±0.3 vs. -1.9±0.6,
p=0.030), in A2C mid inferior (-1.7±0.4 vs. -2.1±0.7, p=0.010), apex
(-1.3±0.2 vs. -1.5±0.5, p=0.023), apical anterior (-1.4±0.3 vs.
-1.7±0.6, p=0.041). Circumferential strain rate measurements were also
lower in CF patients than in healthy controls in the following
parameters: in basal view, in the basal anteroseptal (-2.0±0.4 vs.
-2.4±0.5, p=0.003) and basal anterolateral (-1.6±0.4 vs. -2.0±0.7,
p=0.040); in the medial view, in the mid anterior (-1.7±0.5 vs.
-2.0±0.5, p=0.039), mid inferolateral (-1.7±0.4 vs. -2.0±0.6, p=0.035)
and mid inferoseptal segments (-1.7±0.4 vs. -1.9±0.3, p=0.012) (Tables
3,4).