Coarctation of the aorta, often abbreviated CoA, affects roughly one in several thousand live births and can remain clinically silent until hypertension or heart failure emerges in adulthood. Even after the narrowing is relieved by surgery or stenting, many patients continue to develop hypertension, diastolic dysfunction, and premature cardiovascular disease. Previous work by the same group and others has hinted that eliminating the trans-coarctation pressure gradient does not always normalize left ventricular function or aortic shear stress, suggesting that something beyond the pressure drop itself shapes long-term outcomes. The new study homes in on one candidate: post-stenotic energy dissipation, the irreversible loss of useful mechanical energy that occurs when high-velocity, disturbed flow exiting the narrowing collides with the complex three-dimensional anatomy of the descending aorta.

To dissect this phenomenon, the team analyzed a cohort of twenty patients with coarctation of the aorta. From computed tomography and magnetic resonance imaging, they extracted detailed anatomical features of the aorta, including the centerline topology—the curved path tracing the vessel’s midline—and the variation in cross-sectional area along the descending aorta. These geometric descriptors capture how sharply the aorta bends, how abruptly its caliber changes, and how the vessel’s axis deviates between the coarctation site and the segments immediately downstream. Rather than treating the aorta as a simple tube, the approach quantifies the actual anatomical landscape through which the jet of blood must travel after it exits the stenosis.

On top of the imaging analysis, the researchers built patient-specific multiscale computational simulations that couple three-dimensional aortic hemodynamics with models of cardiac function and systemic circulation. This framework allows the virtual blood flow to respond both to the local anatomy of each patient’s aorta and to the global behavior of the heart and arterial system. Using these simulations, the team quantified energy dissipation per unit volume in the descending aorta—a measure of how much of the blood’s mechanical energy is converted into heat and turbulence rather than forward motion. The multiscale design matters because energy loss in the aorta cannot be interpreted in isolation; it depends on the pressure and flow waveforms delivered by the left ventricle and on the resistance and compliance of the entire circulation.

The central finding is strikingly geometric. Energy dissipation per unit volume in the descending aorta correlates with the combined effect of two quantities: the kinetic energy available in the flow at the coarctation site, and the centerline tangent angle difference between the coarctation and the downstream descending aorta. In plain terms, it is not enough to know how fast the blood is moving as it leaves the narrowing; one must also know how much the vessel’s axis changes direction just downstream. A jet that exits the stenosis into a sharply angled or tortuous segment cannot follow the vessel wall smoothly, and the resulting flow separation, secondary motions, and turbulence dissipate far more energy than the same jet entering a well-aligned segment.

This angle-based insight reframes a familiar clinical observation. Post-stenotic dilatation—the widening of the aorta just beyond a narrowing—has long been recognized on imaging, and computational studies have linked it to the disturbed hemodynamics downstream of stenoses. The new results suggest that the same anatomical misalignment that promotes dilatation also acts as an energy sink, converting the kinetic energy generated by the ventricle into wasted, irreversible losses. Two patients with identical pressure gradients could therefore carry very different energetic burdens depending on the shape of their descending aortas, a distinction that the standard diagnostic metric is blind to.

Crucially, the study connects these downstream losses to the heart itself. The geometric and energetic parameters—the kinetic energy at the coarctation and the centerline angle difference—were found to significantly influence the left ventricular workload expended to compensate for post-stenotic energy loss. In other words, when the aorta’s geometry squanders the energy the heart delivers, the ventricle must do additional work to maintain adequate perfusion of the body. Over years, this chronic energetic penalty plausibly contributes to the left ventricular hypertrophy, diastolic dysfunction, and exercise intolerance documented in adults with repaired coarctation, outcomes that prior clinical studies have linked to abnormal arterial load indices even when resting blood pressure appears controlled.

The implications for clinical practice are substantial. Current guidelines from the American Heart Association and the European Society of Cardiology rely heavily on pressure gradients, imaging-derived indices of narrowing severity, and ventricular function to guide decisions about intervention. The new findings argue for incorporating anatomical and energetic metrics—centerline curvature, angle change, cross-sectional area variation, and computed energy dissipation—alongside pressure gradients when assessing disease severity and cardiac burden. Because the required inputs come from CT and MRI images that patients already undergo, the geometric analysis could in principle be folded into existing imaging workflows, and the computational framework builds on the group’s broader program of non-invasive, patient-specific diagnostic tools for valvular and vascular disease.

The work also resonates with a growing body of literature on cardiovascular energetics. Four-dimensional flow magnetic resonance imaging has been used to measure turbulent kinetic energy in aortic stenosis and coarctation, and studies of hypertrophic cardiomyopathy have shown that individualized computational modeling can reveal energetic inefficiencies invisible to conventional metrics. By identifying a simple, image-derived geometric predictor of energy loss, the McMaster team offers a bridge between high-fidelity simulation and practical clinical assessment. The method’s reliance on centerline morphology—something extractable from standard angiographic and tomographic data—makes it more translatable than approaches requiring specialized flow-sensitive sequences.

Limitations and next steps remain. The cohort comprised twenty patients, and the study, supported by NSERC Discovery and Alliance grants and computational resources from the Digital Research Alliance of Canada, will need validation in larger and more diverse populations, including patients before and after intervention. Longitudinal studies will be required to test whether geometrically driven energy dissipation predicts ventricular remodeling, hypertension, or clinical events over time. Still, the message is clear and potentially practice-changing: in coarctation of the aorta, the pressure drop across the narrowing is only the opening chapter of the story. The shape of the vessel that receives the jet—the bends, the angles, the tapering of the descending aorta—determines how much of the heart’s energy survives the journey, and how hard the ventricle must work to make up the difference. Reading the aorta’s centerline, the study suggests, may be as important as measuring its pressures.

Subject of Research: Geometric determinants of post-stenotic flow energy loss and left ventricular workload in coarctation of the aorta

Article Title: Geometric Determinants of Post-stenotic Energetics in Coarctation of Aorta: Linking Centerline Morphology to Downstream Energy Loss

Article References: Daeian, M., Karbassi, A., Ganame, J., Smith, S., & Keshavarz-Motamed, Z. (2026). Geometric Determinants of Post-stenotic Energetics in Coarctation of Aorta: Linking Centerline Morphology to Downstream Energy Loss. Annals of Biomedical Engineering. https://doi.org/10.1007/s10439-026-04351-y

Image Credits: AI Generated

DOI: 10.1007/s10439-026-04351-y

Keywords: aortic coarctation, hemodynamics, energy dissipation, centerline morphology, left ventricular workload, computational fluid dynamics, descending aorta, pressure gradient, patient-specific modeling, cardiac function, viscous dissipation, medical imaging

The research, conducted by Maoting Chen and Qianling Wei of the Department of Critical Care Medicine at West China Hospital of Sichuan University and the West China School of Nursing, examined the records of 124 pediatric patients who were hospitalized in intensive care wards after complex cardiac surgery between June 30, 2008 and December 31, 2022. The researchers asked a deceptively straightforward question: did children who received daily oral care during their perioperative period experience fewer adverse clinical events than those who did not? The two outcomes of primary interest were sepsis, the life-threatening systemic response to infection, and deteriorated heart function, both of which are among the most feared complications following pediatric cardiac procedures.

The answer, according to the study’s statistical analysis, was yes. Among the 124 children studied, sepsis occurred in 16 patients, an incidence of 12.9 percent, while deteriorated heart function was observed in 23 patients, or 18.5 percent. When the researchers applied multivariate logistic regression, a statistical technique that adjusts for the influence of multiple variables simultaneously, they found that children who had not received oral health care faced markedly higher risks. In the study’s fully adjusted model, the risk of sepsis was significantly elevated in patients without oral care, with an adjusted odds ratio of 2.32 and a 95 percent confidence interval of 1.36 to 4.32, corresponding to a P value of 0.026. The risk of deteriorated heart function was also higher, with an adjusted odds ratio of 1.83, a confidence interval of 1.09 to 3.14, and a P value of 0.039.

Those numbers translate into a compelling clinical message. An odds ratio of 2.32 means that, after accounting for other factors, children who did not receive daily oral care had more than twice the odds of developing sepsis compared with those who did. For deteriorating cardiac function, the odds were nearly doubled. In both cases, the confidence intervals exclude the value of 1.0, which is the statistical threshold indicating no effect, and the P values fall below the conventional 0.05 significance level. The researchers also performed sensitivity analyses, which are repeated analyses designed to test whether a finding holds up under different assumptions or model specifications, and these continued to indicate that daily oral care contributed to a reduced risk of both sepsis and declining cardiac function in pediatric patients after cardiac surgery.

Perhaps the most intriguing detail to emerge from the study concerns the choice of rinsing agent. The negative association between oral health and adverse outcomes, meaning the protective relationship, was stronger among patients who used a 2 percent oral chlorhexidine rinse than among those who used 0.9 percent physiological saline. Chlorhexidine is an antiseptic agent widely used in hospitals to suppress the microbial load in the mouth, and the finding suggests that the composition of the oral rinse may matter, not merely the act of rinsing itself. Saline, while helpful for mechanical clearance of debris and microorganisms, lacks the sustained antimicrobial activity that chlorhexidine provides. This nuance could inform future protocols for oral hygiene in pediatric intensive care settings.

The biological rationale behind these findings is grounded in well-established oral-systemic pathways. The mouth harbors a dense and diverse microbial community, and in critically ill patients this community can shift toward pathogenic species. Intubation, sedation, and mechanical ventilation, all routine in complex cardiac surgery, bypass the natural defenses of the upper airway and can allow oral bacteria to colonize the lower respiratory tract. From there, microorganisms or their products can enter the bloodstream, triggering the systemic inflammatory cascade that defines sepsis. Inflammation itself can further stress a heart that has just been subjected to the trauma of cardiopulmonary bypass and surgical repair, creating a vicious cycle in which infection and cardiac dysfunction reinforce one another. By reducing the microbial burden in the mouth, daily oral care may interrupt this cycle at its earliest and most accessible stage.

Children undergoing complex cardiac surgery represent a particularly high-risk population for these mechanisms. Their immune systems are still developing, their physiological reserves are limited, and the surgical procedures they undergo are among the most invasive in pediatric medicine. Postoperative sepsis in this group is associated with prolonged intensive care stays, additional organ support, and increased mortality, while deteriorating cardiac function can necessitate escalated mechanical support or reintervention. Any intervention that is inexpensive, noninvasive, and deliverable at the bedside therefore carries substantial potential value for this population, and oral care fits that description precisely.

The study’s design warrants careful interpretation. As a retrospective analysis, it examined existing records rather than prospectively assigning patients to receive or forgo oral care, which means that unmeasured differences between the two groups could have influenced the results. The authors note that the research was approved by the Ethics Committee of West China Hospital of Sichuan University in accordance with the Helsinki Declaration and national regulations, and that informed consent from patients’ parents or legal guardians was waived because most individuals had been discharged and could not be contacted. The use of multivariate regression and sensitivity analysis strengthens the findings, but the association reported here is exactly that, an association, and randomized controlled trials would be needed to establish a definitive causal relationship between daily oral care and reduced adverse events.

Even with those caveats, the study contributes to a broader shift in how critical care medicine views the mouth. Oral health has been increasingly linked to a range of clinical complications, and maintaining good oral care has become recognized as one of the important interventions to reduce the risk of adverse clinical events. Yet, as the authors point out, the association of oral health care with sepsis and cardiac function has remained controversial, with prior evidence inconsistent. By focusing specifically on children after complex cardiac surgery, a population in which both outcomes are frequent and consequential, and by demonstrating statistically significant associations for both, the new research provides further evidence for the importance of oral health in reducing adverse clinical events, particularly in critically ill pediatric patients.

The practical implications are likely to resonate with intensive care teams worldwide. Daily oral care is among the least expensive interventions available in an ICU, requiring little more than trained nursing time, toothbrushes or swabs, and a rinsing solution. If the associations observed here are confirmed in prospective studies, standardizing perioperative oral hygiene protocols for children undergoing cardiac surgery could become a low-cost, high-value component of postoperative care, with the choice of chlorhexidine over saline potentially amplifying the benefit. For the families of the hundreds of thousands of children who undergo cardiac surgery each year, the message from this research is quietly remarkable: one of the keys to protecting a repaired heart may lie not in the operating theater but in the daily, unglamorous care of a child’s mouth.

Subject of Research: The association between perioperative oral care and postoperative sepsis and cardiac function in children after complex cardiac surgery

Article Title: The association between perioperative oral care and adverse clinical events after complex cardiac surgery in children

Article References: Chen, M., & Wei, Q. (2026). The association between perioperative oral care and adverse clinical events after complex cardiac surgery in children. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07406-0

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07406-0

Keywords: oral care, sepsis, cardiac function, pediatric cardiac surgery, intensive care unit, chlorhexidine, oral hygiene, children, critical care, infection prevention, retrospective study, BMC Pediatrics