Regional Heterogeneity of Myocardial Remodeling in Aortic Valve Disease: A Segmental Strain CMR Study.

Background: Aortic valve diseases impose a substantial hemodynamic burden on the left ventricle (LV), leading to heterogeneous myocardial remodeling that may persist even after surgical correction. Cardiovascular magnetic resonance (CMR) has emerged as the gold standard for noninvasive myocardial tissue characterization, with strain analysis providing valuable insights into subclinical dysfunction.While global strain parameters are well established, they may overlook regional myocardial abnormalities that carry prognostic and therapeutic implications. Segmental strain (SS), particularly when derived from Feature Tracking Imaging, offers the potential to detect subtle, region-specific changes in myocardial mechanics before and after surgical aortic valve replacement (SAVR).

Methods: Patients followed at the Valvular Heart Disease Clinic of InCor-HCFMUSP were included. Cardiac magnetic resonance (CMR) imaging was performed within six months prior to surgical aortic valve replacement (SAVR) using a 1.5T scanner and repeated between six and ten months postoperatively. Image analysis was conducted using Circle Cardiovascular Imaging software (CVI42) to assess left ventricular (LV) strain parameters, including radial strain (SRS), circumferential strain (SCS), and longitudinal strain (SLS), in both short- and long-axis views. Strain assessment was based on the American Heart Association (AHA) 16-segment model, excluding the apical segments. To compare pre- and postoperative strain parameters, the non-parametric Wilcoxon signed-rank test was applied to paired samples, accounting for variations across LV wall segments within each patient.

Results: We included 105 patients (74 with aortic stenosis and 31 with aortic regurgitation), totaling 1,688 myocardial segments analyzed. In the AS group, SCS showed a significant reduction in all segments, except for anterior vs. lateral in the pre-SAVR period (p = 0.107) and anterior vs. inferior in the post-SAVR period (p = 0.205). For SRS, most segments showed a significant reduction, except for anterior x lateral pre-SAVR (p = 0.1457) and anterior x inferior post-SAVR (p = 0.3141). In the AR group, SCS showed a significant reduction in almost all segments, except for septal x inferior pre-SAVR (p = 0.5285) and anterior x inferior post-SAVR (p = 0.7326). For SRS, significant differences were observed in most segments, except for septal vs. inferior pre-SAVR (p = 0.4482) and inferior vs. lateral post-SAVR (p = 0.6401).

Conclusion: In aortic valve disease, segmental strain analysis uncovered a heterogeneous pattern of myocardial dysfunction that became even more evident after surgical correction. These findings highlight the complexity of regional myocardial adaptation and suggest that conventional global metrics may underestimate subclinical alterations in contractility and remodeling. Future multicenter studies with larger cohorts are essential to validate these results and determine their prognostic and therapeutic implications in the postoperative setting.

Preoperative demographic and clinical characteristics of the studied individuals.

	Total (n=105)	AR (n=32)	AS (n=73)	P
AGE	69.6 ± 33.6	54.6 ± 2.49	64.1 ± 0.98	0.0001
SEX FEMALE MALE				0.114
	38 (36.1%) 67 (63.8%)	8 (25%) 24 (75%)	30 (41.0%) 43 (58.9%)
DIABETES MELLITUS	32 (30.4%)	4 (12,5%)	28 (38.3%)	0.008
SAH	94 (89.5%)	30 (3.2%)	73 (100%)	0.349
CAD	20 (19.0%)	3 (9.3%)	17 (23.2%)	0.095
DYSLIPIDEMIA	76 (72.3%)	20 (62.5%)	56 (76.7%)	0.134
MEDICATIONS ACEI/ARB ß-BLOQUER DIURETICS STATIN
	70 (66.6%)	27 (84.3%)	43 (58.9%)	0.011
	35 (33.3%)	32 (100%)	73 (100%)	0.294
	72 (68.5%)	22 (68.7%)	50 (68.4%)	0.979
	55 (52.2%)	14 (43.7%)	41 (56.1%)	0.241

Data are expressed as mean ± standard deviation for numerical variables and as absolute values and percentages for categorical variables. AR= aortic faliture ; AS= aortic stenosis; SAH= Systemic Arterial Hypertension; CAD= Coronary Artery Disease; ACEI= Angiotensin-Converting Enzyme inhibitor ;ARB= Angiotensin Receptor Blocker;Figure 1: (A–B) Representation of regional circumferential strain obtained by cardiovascular magnetic resonance before (A) and after (B) surgical correction in patients with aortic regurgitation. (A) A heterogeneous contractility pattern is observed, with significantly greater strain in the septal segment compared to the anterior one, with the septum being the least contractile segment (p = 0.0001). (B) After surgery, regional heterogeneity becomes more pronounced, with emphasis on the difference between the septal and lateral segments (p = 0.0001). A more marked worsening in the septum and relative preservation of the lateral segment compared to the preoperative exam is also noted.