RESUMO
BACKGROUND: Sleep disordered breathing (SDB) is a frequent comorbidity in cardiac disease patients. Nevertheless, the prevalence and relationship between SDB and severe primary mitral regurgitation (PMR) has not been well investigated to date. METHODS: A cohort of 121 patients with significant PMR undergoing mitral valve surgery were prospectively enrolled and received a cardiorespiratory single night polygraphy screening using ApneaLink before surgery. Eighty-two of them underwent a follow-up examination including a follow-up single-night sleep study 3 months after surgery. RESULTS: The mean age of patients was 65.3 ± 12.0 years. Sixty patients (49.6%) were female. The mean EuroSCORE II was 2.5 ± 2.4%. Initially, 91 (75.2%) patients presented with SDB, among whom 50.4% (46 patients, 38.0% of total cohort) were classified as moderate to severe. These patients tended to require significantly longer postoperative intensive care and mechanical ventilation. Among the 82 patients who completed follow-up exams, mitral valve surgery led to a significant reduction in relevant SDB (20.7%). The apnea-hypopnea index (from 11/h [4;18] to 4/h [3;14] (p = 0.04)), the oxygenation-desaturation index (from 8/h [3;18] to 5/h [3;12] (p = 0.008)) as well as the saturation time below 90% (from 32 min [13;86] to 18 min [5;36] (p = 0.005)), were all shown to be improved significantly. CONCLUSION: The prevalence of SDB is very high in patients with severe primary mitral regurgitation and may contribute to postoperative complications and prolonged intensive care. A significantly reduced but still high prevalence of SDB was observed 3 months after mitral valve surgery, highlighting the bidirectional relationship between SDB and heart failure.
RESUMO
The risk of left ventricular (LV) and right ventricular (RV) maladaptation after surgery for isolated primary mitral regurgitation (PMR) is poorly defined. We aimed to evaluate LV and RV contractile function using speckle-tracking analysis alongside with quantification of exercise tolerance in patients with PMR after mitral valve surgery. All consecutive patients with symptomatic PMR undergoing mitral valve surgery between July 2015 and May 2017 were prospectively enrolled. Sequential echocardiographic studies along with clinical assessment were performed before and three months after surgery. Mean age in 138 patients was 65.8 ± 12.7 years, 48.2% (66) of whom were female. Mean LV ejection fraction decreased from 57 ± 12% to 50 ± 11% (p < 0.001), LV global longitudinal strain deteriorated from -19.2 ± 4.1% to -15.7 ± 3.8% (p < 0.001), and mechanical strain dispersion increased from 88 ± 12 to 117 ± 115 ms (p = 0.004). There was a reduction in tricuspid annulus plane systolic excursion from 22 ± 5 mm to 18 ± 4 mm (p < 0.001), as well as a slight deterioration of RV free wall mean longitudinal strain from -16.9 ± 5.6% to -15.7 ± 4.1% (p = 0.05). The rate of moderate to severe tricuspid regurgitation significantly decreased (p < 0.005). Regarding exercise tolerance, the New York Heart Association class improved (p < 0.001) and the walking distance increased (p < 0.001). During mid-term follow up after surgery for PMR, a deterioration of LV and RV contractile function measures could be observed. However, the clinical status, LV dimensions, and concomitant tricuspid regurgitation improved which in particular imply more effective RV contractile pattern.
