Long-term outcome of COVID-19 patients with acute kidney injury requiring kidney replacement therapy.

BACKGROUND: Limited data existed on the burden of coronavirus disease 2019 (COVID-19) renal complications and the outcomes of the most critical patients who required kidney replacement therapy (KRT) during intensive care unit (ICU) stay. We aimed to describe mortality and renal function at 90 days in patients admitted for COVID-19 and KRT. METHODS: A retrospective cohort study of critically ill patients admitted for COVID-19 and requiring KRT from March 2020 to January 2022 was conducted in an Italian ICU from a tertiary care hospital. Primary outcome was mortality at 90 days and secondary outcome was kidney function at 90 days. RESULTS: A cohort of 45 patients was analyzed. Mortality was 60% during ICU stay and increased from 64% at the time of hospital discharge to 71% at 90 days. Among 90-day survivors, 31% required dialysis, 38% recovered incompletely, and 31% completely recovered renal function. The probability of being alive and dialysis-free at 3 months was 22%. CONCLUSIONS: Critically ill patients with COVID-19 disease requiring KRT during ICU stay had elevated mortality rate at 90 days, with low probability of being alive and dialysis-free at 3 months. However, a non-negligible number of patients completely recovered renal function.

Oxygen Uptake Attenuation at Ventilatory Threshold in Men With Coronary Artery Disease.

PURPOSE: Maximal oxygen uptake ((Equation is included in full-text article.)O2) and ventilatory threshold (VT) are widely used to assess cardiorespiratory fitness in healthy people, as well as in patients with various clinical conditions. The aim of this study was to determine whether an attenuation of (Equation is included in full-text article.)O2 occurs above the VT in patients with stable coronary artery disease. METHODS: A total of 33 male patients participating in an outpatient cardiac rehabilitation/secondary prevention program underwent maximal incremental cycle ergometry at increasing pedaling cadences up to the limit of tolerance. Ventilatory gas-exchange variables were measured breath by breath while work rate was recorded continuously. Ventilatory threshold was determined by a dual linear regression model (V-slope analysis). RESULTS: Four patients were excluded from the analysis because they were unable to pedal at the increasing cadences required by the protocol. The remaining 29 patients successfully completed the test without complications or evidence of significant ST segment depression. The slope of the (Equation is included in full-text article.)O2/work rate relationship above the VT decreased significantly (-44.6% on average) in 23 of the 26 patients in which VT was able to be determined. (Equation is included in full-text article.)O2 at the start of (Equation is included in full-text article.)O2 attenuation ((Equation is included in full-text article.)O2att) and at VT were highly correlated and in strong agreement (1637 ± 451 mL/min vs 1650 ± 473 mL/min, r = 0.96, P < .01). CONCLUSIONS: (Equation is included in full-text article.)O2att does occur and coincides with the VT in the majority of patients tested with stable coronary artery disease.

Association between VO2 peak estimated by a 1-km treadmill walk and mortality. A 10-year follow-up study in patients with cardiovascular disease.

PURPOSE: The aim of this study is to assess the association between peak oxygen uptake (VO2 peak), determined using a perceptually regulated 1-km walking test (1k-TWT), and all-cause mortality in cardiac patients. METHODS: 1255 male patients, aged 25-85 years, completed a moderate 1k-TWT to estimate VO2 peak. Subjects were followed for all-cause mortality for up to 10 years. Cox proportional hazard models were employed to determine variables associated with mortality. Based on the estimated VO2 peak, the sample was subdivided into quartiles and mortality risks were calculated. To assess the discriminatory accuracy of the estimated VO2 peak for estimating survival, receiver-operating-characteristics curves were constructed. RESULTS: During a median 8.2 year follow-up, a total of 141 deaths from any cause occurred, yielding an average annual mortality of 1.4%. The strongest predictor of all-cause mortality was the estimated VO2 peak (c-statistic 0.71, 95% confidence intervals: 0.69-0.74, P<0.0001). Survival decreased in a graded fashion from the highest estimated VO2 peak quartile to the lowest quartile. Compared to the lowest quartile, the hazard ratios (95% confidence intervals) for the second, third, and fourth quartiles were 0.77 (0.35-1.33), 0.43 (0.20-0.91), and 0.16 (0.05-0.54) respectively (P for trend <0.0001). An 89% reduction in mortality risk was observed among a subset of subjects in the fittest quartile who improved their estimated VO2 peak over the follow-up period relative to subjects in the least fit quartile who did not improve. CONCLUSION: VO2 peak estimated by a novel 1k-TWT predicts survival in subjects with stable cardiovascular disease.

Treadmill walking speed and survival prediction in men with cardiovascular disease: a 10-year follow-up study.

OBJECTIVE: To determine whether the walking speed maintained during a 1 km treadmill test at moderate intensity predicts survival in patients with cardiovascular disease. DESIGN: Population-based prospective study. SETTING: Outpatient secondary prevention programme in Ferrara, Italy. PARTICIPANTS: 1255 male stable cardiac patients, aged 25-85 years at baseline. MAIN OUTCOME MEASURES: Walking speed maintained during a 1 km treadmill test, measured at baseline and mortality over a median follow-up of 8.2 years. RESULTS: Among 1255 patients, 141 died, for an average annual mortality of 1.4%. Of the variables considered, the strongest predictor of all-cause mortality was walking speed (95% CI 0.45 to 0.75, p<0.0001). Based on the average speed maintained during the test, participants were subdivided into quartiles and mortality risk adjusted for confounders was calculated. Compared to the slowest quartile (average walking speed 3.4 km/h), the relative mortality risk decreased for the second, third and fourth quartiles (average walking speed 5.5 km/h), with HRs of 0.73 (95% CI 0.46 to 1.18); 0.54 (95% CI 0.31 to 0.95) and 0.20 (95% CI 0.07 to 0.56), respectively (p for trend <0.0001). Receiver operating curve analysis showed an area under the curve of 0.71 (p<0.0001) and the highest Youden index (0.35) for a walking speed of 4.0 km/h. CONCLUSIONS: The average speed maintained during a 1 km treadmill walking test is inversely related to survival in patients with cardiovascular disease and is a simple and useful tool for stratifying risk in patients undergoing secondary prevention and cardiac rehabilitation programmes.

Peak oxygen uptake prediction from a moderate, perceptually regulated, 1-km treadmill walk in male cardiac patients.

PURPOSE: To determine whether a moderate 1-km treadmill walking test (1KTWT) could be used to predict peak oxygen uptake VO(2)peak) in patients with cardiovascular disease. METHODS: One hundred seventy-eight male patients, aged 38 to 83 years, completed a VO(2)peak treadmill test and a 1KTWT using a self-regulated intensity of 11 to 13 of 20 on the Borg scale. Multivariable regression analysis was used to develop equations for predicting VO(2)peak in a development group (n = 110), both for subjects prescribed and not prescribed a ß-blocking agent (BB/NBB, 66/44). These equations were then applied to a cross-validation and reproducibility group (n = 68, BB/NBB, 37/31), who completed the protocol twice within 2 weeks. RESULTS: Analysis from 1KTWT in the development group showed that age, body mass index, walking speed, and heart rate were the most potent predictors of VO(2)peak. Measured and predicted VO(2)peak were not significantly different, and were strongly associated among both the NBB (r = 0.81, P < .0001) and BB (r = 0.69, P < .0001) groups, with a mean residual of approximately 1.0 mL·kg(-1)·min(-1). When applied to the cross-validation and reproducibility group, the equations similarly yielded strong associations (r = 0.64, P < 0.001 and r = 0.71, P < 0.001 for the NBB and BB groups, respectively), with no significantly differences between measured and predicted VO(2)peak. Mean test-retest differences for measured and predicted VO(2)peak were between 0.1 and -0.5 mL·kg(-1)·min(-1). CONCLUSIONS: Equations developed from the 1KTWT accurately predicted VO(2)peak in patients with cardiovascular disease. The model may represent a valid, low cost, and simple tool for indirect estimations of cardiorespiratory fitness in an outpatient setting.