Above‐Threshold Ambulatory Systolic Pressure and Left Ventricular Mass in Chronic Kidney Disease: Does AUC Add Beyond Mean Pressure?

Figures

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  FIGURE 1. Visual explanation of total above‐threshold AUC and its two components. Panels A and B show two deidentified ambulatory blood pressure monitoring (ABPM) profiles with similar daytime and nighttime mean SBP but different total above‐threshold AUC. Points are recorded ABPM measurements, and adjacent points are connected linearly. Dashed gray lines show the period‐specific thresholds, gold lines show period mean SBP, and red shading shows the complete above‐threshold burden. Panel C separates AUCtotal into the part attributable to daytime and nighttime mean SBP (AUCmean) and the remaining part not captured by those means (AUCremaining).

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  FIGURE 2. Associations of daytime and nighttime ambulatory SBP summaries with LVMI. Points and lines show adjusted LVMI differences and 95% confidence intervals from the 25th to 75th percentile of each exposure. Daytime and nighttime terms were entered jointly within the mean‐SBP and AUC models. AUCremaining was added to the model containing daytime and nighttime mean SBP. All analyses used the same 212 patients and core covariates. SBP, systolic blood pressure; AUC, area under the curve; CI, confidence interval.

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  FIGURE 3. Internal model performance across the primary and secondary model comparisons. Points and lines show paired differences in LVMI error from repeated internal cross‐validation, with 95% paired‐bootstrap intervals. Negative values favor the first model named. The comparisons evaluate the joint daytime/nighttime AUC model against the joint daytime/nighttime mean‐SBP model, the mean‐SBP model plus AUCremaining against the mean‐SBP model alone, and AUCmean+AUCremaining against AUCmean alone. The last comparison evaluates the two components within AUC and is not a test beyond the complete period means. These comparisons assess internal performance and do not establish external validity. AUC, area under the curve; SBP, systolic blood pressure; LVMI, left ventricular mass index.

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  FIGURE 4. Left ventricular geometry distribution and adjusted associations with AUC. Panel A shows normal geometry, concentric remodeling, eccentric LVH, and concentric LVH across AUC quartiles; each quartile included 53 patients. The overall four‐category distribution differed significantly across quartiles (Pearson P < 0.001). The concentric LVH trend was P < 0.001, although its proportion was not strictly monotonic because Q2 was lower than Q1. Panel B shows adjusted category‐specific odds ratios and 95% confidence intervals per 100 mmHg·h, with normal geometry as the reference. The four‐category geometry outcome is nominal; therefore, the adjusted multinomial model, rather than an ordered‐category trend, was used for inference. These analyses were exploratory. AUC, area under the curve; LVH, left ventricular hypertrophy; OR, odds ratio.