The Effect of Positive Pressure Ventilation on Acute Kidney Injury in COVID-19 Patients with Acute Respiratory Distress Syndrome: An Observational Study.

INTRODUCTION: Acute kidney injury (AKI) is frequent in critically ill COVID-19 patients and is associated with a higher mortality risk. By increasing intrathoracic pressure, positive pressure ventilation (PPV) may reduce renal perfusion pressure by reducing venous return to the heart or by increasing renal venous congestion. This study's aim was to evaluate the association between AKI and haemodynamic and ventilatory parameters in COVID-19 patients with ARDS. METHODS: This is a single-centre retrospective observational study. Consecutive patients diagnosed with COVID-19 who met ARDS criteria and required invasive mechanical ventilation were enrolled. The relationship between respiratory and haemodynamic parameters influenced by PPV and AKI development was evaluated. AKI was defined according to KDIGO criteria. AKI recovery was evaluated a month after ICU admission and patients were classified as "recovered," if serum creatinine (sCr) value returned to baseline, or as having "acute kidney disease" (AKD), if criteria for AKI stage 1 or greater persisted. The 6-month all-cause mortality was collected. RESULTS: A total of 144 patients were included in the analysis. AKI occurred in 69 (48%) patients and 26 (18%) required renal replacement therapy. In a multivariate logistic regression analysis, sex, hypertension, cumulative dose of furosemide, fluid balance, and plateau pressure were independently associated with AKI. Mortality at 6 months was 50% in the AKI group and 32% in the non-AKI group (p = 0.03). Among 36 patients who developed AKI and were discharged alive from the hospital, 56% had a full renal recovery after a month, while 14%, 6%, and 14% were classified as having an AKD of stage 0, 2, and 3, respectively. CONCLUSIONS: In our cohort, AKI was independently associated with multiple variables, including high plateau pressure, suggesting a possible role of PPV on AKI development. Further studies are needed to clarify the role of mechanical ventilation on renal function.

Right Intraventricular Dyssynchrony in Idiopathic, Heritable, and Anorexigen-Induced Pulmonary Arterial Hypertension: Clinical Impact and Reversibility.

OBJECTIVES: The aim of this study was to determine the prevalence of right intraventricular dyssynchrony, its determinants and prognostic impact in idiopathic, heritable, and anorexigen-induced pulmonary arterial hypertension. BACKGROUND: Right ventricular dyssynchrony has been described in pulmonary arterial hypertension, but no evidence is available on its prognostic impact and evolution after therapy. METHODS: In 83 consecutive therapy-naïve patients, right ventricular dyssynchrony was evaluated by 2-dimensional speckle-tracking echocardiography calculating the standard deviation of the times to peak-systolic strain for the 4 mid-basal right ventricular segments (RV-SD4). After baseline (World Health Organization [WHO] class, pulmonary hemodynamics, 6-min walk test [6 MWT]), a second assessment was performed after 12 months or when clinical worsening occurred. RESULTS: Patients with right ventricular dyssynchrony (RV-SD4 >18 ms) had advanced WHO class, worse 6 MWT, right ventricular remodeling, and hemodynamic profile compared with patients ≤ 18 ms. Determinants of dyssynchrony included pulmonary vascular resistance, QRS duration, and right ventricular end-diastolic area (r(2) = 0.38; p < 0.000001). At 12 months, 32.5% of patients presented clinical worsening (actuarial rates: 19% at 6 months, 31% at 1 year). Multivariable models for clinical worsening prediction showed that the addition of RV-SD4 to clinical and hemodynamic variables (WHO IV, 6 MWT, and cardiac index) significantly increased the prognostic power of the model (0.74 vs. 0.81; p = 0.005, 95% confidence interval [CI]: 0.02 to 0.11). Receiver operating characteristic analysis identified RV-SD4 ≥ 23 ms as the best cutoff value for clinical worsening prediction (95% negative predictive value). At 12 months, normalization of dyssynchrony was achieved in patients with a large reduction of pulmonary vascular resistance (-42 ± 4%). CONCLUSIONS: Right ventricular dyssynchrony is frequent in pulmonary arterial hypertension, is an independent predictor of clinical worsening, and might regress during effective treatments.

Right ventricular remodeling in idiopathic pulmonary arterial hypertension: adaptive versus maladaptive morphology.

BACKGROUND: Although increased pulmonary pressure is caused by changes in the pulmonary vasculature, prognosis in idiopathic pulmonary arterial hypertension (IPAH) is strongly associated with right ventricular (RV) function. The aim of this study was to describe the best RV adaptive remodeling pattern to increased afterload in IPAH. METHODS: In 60 consecutive patients with IPAH, RV morphologic and functional features were evaluated by echocardiography and cardiac magnetic resonance imaging. To address the question of the best RV adaptation pattern, we divided the study population into two groups by the median value of RV mass/volume ratio (0.46) because this parameter allows the distinction between RV eccentric (≤0.46) and concentric hypertrophy (>0.46). The two groups were compared for RV remodeling and systolic function parameters, World Health Organization class, pulmonary hemodynamics, and 6-minute walk test. RESULTS: Despite similar pulmonary vascular resistance, mean pulmonary pressure, and compliance, patients with eccentric hypertrophy had advanced World Health Organization class and worse 6-minute walk test, hemodynamics, RV remodeling, and systolic function parameters compared with patients with concentric hypertrophy. The group with concentric hypertrophy had higher RV to pulmonary arterial coupling compared with the group with eccentric hypertrophy (1.24 ± 0.26 vs 0.83 ± 0.33, p = 0.0001), indicating higher RV efficiency. A significant correlation was found between pulmonary vascular resistance and RV to pulmonary arterial coupling (r = -0.55, r(2) = 0.31, p = 0.0001), with patients with RV mass/volume ratio > 0.46 at the higher part of the scatterplot, confirming more adequate RV function. CONCLUSIONS: Concentric hypertrophy might represent a more favorable RV adaptive remodeling pattern to increased afterload in IPAH because it is associated with more suitable systolic function and mechanical efficiency.

Right ventricular dyssynchrony in idiopathic pulmonary arterial hypertension: determinants and impact on pump function.

BACKGROUND: Right ventricular (RV) dyssynchrony has been described in pulmonary arterial hypertension (PAH), but no evidence is available on its morphologic determinants and its effect on systolic function. The aim of this study was to evaluate the morphologic determinants of RV dyssynchrony by echocardiographic and cardiac magnetic resonance imaging and its effect on systolic function. METHODS: In 60 consecutive idiopathic PAH (IPAH) patients with narrow QRS, RV dyssynchrony was evaluated by 2D speckle-tracking echocardiography, calculating the standard deviation of the times to peak systolic strain for the four mid-basal RV segments (RV-SD4). Patients were grouped by the median value of RV-SD4 (19 milliseconds) and compared for RV remodeling and systolic function parameters, WHO class, pulmonary hemodynamics and 6-minute walk test (6MWT). RESULTS: Despite similar pulmonary vascular resistance and mean pulmonary arterial pressure, patients with RV-SD4 at >19 milliseconds had advanced WHO class and worse 6MWT, RV hemodynamics, RV remodeling and systolic function parameters compared with patients at ≤19 milliseconds. The morphologic determinants of RV dyssynchrony resulted RV end-diastolic area, LV diastolic eccentricity index and RV mass volume ratio (r = 0.69, r(2) = 0.47, p < 0.0001). Finally, we found a significant inverse correlation between RV mid-basal segments post-systolic shortening time and cardiac index (r = -0.64, r(2) = 0.41, p = 0.001), accounting for the significant correlation between RV-SD4 and cardiac index (r = 0.57, r(2) = 0.32, p = 0.003). CONCLUSIONS: In IPAH with narrow QRS, RV dyssynchrony is associated with RV dilation and eccentric hypertrophy pattern, suggesting a role of segmental wall stress heterogeneity as the major determinant of mechanical delay. Post-systolic shortening, as inefficient contraction, contributes to pump dysfunction.

Systemic sclerosis patients with and without pulmonary arterial hypertension: a nailfold capillaroscopy study.

OBJECTIVE: Pulmonary arterial hypertension (PAH) is a complication of SSc due to increased vascular resistance, and abnormal vascularity is a well-known feature of the disease as shown by nailfold videocapillaroscopy (NVC). This study investigated for specific NVC changes in SSc patients with and without PAH to assess any useful difference. METHODS: Twenty-four SSc patients, 12 with PAH and 12 without, entered the study. Evidence of PAH was defined as increased systolic pulmonary artery pressure (PAP) (≥35 mmHg), indirectly assessed by echocardiography and confirmed by right heart catheterization (mPAP > 25 mmHg). NVC was performed, and a semi-quantitative rating scale, a rating system for avascular areas and a specific NVC pattern evaluation, namely early, active and late, were used. RESULTS: An NVC score >1 was more frequently found in patients with PAH than those without, 11 cases (92%) vs 5 cases (42%) (P = 0.03); an avascular areas grade >1 was present in 10 (83%) and 2 (17%) cases, respectively (P = 0.003); and a more severe NC pattern (active/late) was described in 11 (92%) and 5 (42%) patients, respectively (P = 0.03). When we compared the mPAP with NVC parameters, we found significant correlations between mPAP values and the NVC score (P < 0.005) and with the avascular areas score (P < 0.001). CONCLUSION: Our results underline the relevance of early microvascular assessment in patients at risk of developing a severe complication such as PAH that can amplify the systemic microvascular impairment in SSc. More severe NVC abnormalities should lead to strict cardiopulmonary surveillance and a complete NVC study is indicated.

Pulmonary arterial dilatation in pulmonary hypertension: prevalence and prognostic relevance.

OBJECTIVES: Pulmonary arterial dilatation is considered a consequence of chronic pulmonary hypertension (PH), but despite its relatively common detection, its prevalence and prognostic impact have not yet been systematically investigated. The aim of the study was to investigate these factors in a relatively large cohort of severe PH patients. METHODS: One hundred and forty-one consecutive patients diagnosed with PH were monitored for a mean of 957 days. Data including functional class, exercise capacity, invasive hemodynamics and pulmonary artery (PA) echo/CT scan measurement were performed and outcomes prospectively collected. RESULTS: PA dilatation is a common feature, present in the 76.6% of cases in this cohort of severe PH patients. Survival at 1, 2 and 3 years was 83, 71 and 58%, respectively. On univariate analysis, the baseline variables associated with a poor outcome were related to pulmonary arterial hypertension associated with connective tissue disease (CDT-PAH), New York Heart Association (NYHA) functional class, 6-min walk test and right atrial pressure. On multivariate analysis only CDT-PAH and NYHA functional class remained independently associated with poor survival. CONCLUSIONS: PA dilatation is commonly detected in severe PH patients and is not associated with an increased risk of death.