Page 74 - Advanced echocardiography in characterization and management of patients with secondary mitral regurgitation
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Chapter four. Regurgitant Volume/Left Ventricular End-Diastolic Volume Ratio
ratio (<20%). Patients with a low RVol/EDV ratio (<20%) were more frequently treated with cardiac resynchronization therapy, whereas those with a high ratio (≥20%) more frequently underwent surgical MV repair (Table 3).
Table 3. Device and Mitral Valve Interventions During Follow-Up According to RVol/EDV Ratio
  Device therapy CRT-PM CRT-ICD
MV interventions Surgical MVr Surgical MVR MitraClip
Total Population (N = 379)
8 (2) 191 (50)
156 (41) 2 (0.5) 76 (20)
RVol/EDV
Ratio <20% (n = 244)
5 (2) 157 (64)
80 (33) 1 (0.4) 43 (18)
RVol/EDV
Ratio ≥20% (n = 135)
3 (2) 34 (25)
76 (56) 1 (0.7) 33 (24)
p Value
0.911 <0.001
<0.001 0.670 0.112
 Values are n (%).
CRT = cardiac resynchronization therapy; ICD = implantable cardioverter-defibrillator; MV = mitral valve; MVr = mitral valve repair; MVR = mitral valve replacement; PM = pacemaker; other abbreviations as in Table 1.
Survival analysis
During median follow-up of 50 months (IQR: 26 to 94 months) 199 (52.5%) patients of the total study population died, including 169 (44.6%) who died during medical treatment. When considering patients receiving medical therapy only, patients with a high RVol/EDV ratio (≥20%) had higher mortality rates than those with a low RVol/ EDV ratio (<20%), although the difference did not reach statistical significance (5-year estimated rates 24.1% vs. 18.4% respectively; p = 0.077) (Figure 2A). Changes in HR across the range of RVol/EDV ratio (as a continuous variable) for all-cause mortality before any MV interventions are demonstrated with a fitted spline curve in Figure 3A. The assumption of linearity was not violated (χ2 = 0.849; p = 0.36). When considering patients on medical therapy only, RVol/EDV ratio was significantly associated with all- cause mortality after correcting for age and renal function (HR per 5% increment: 1.08; 95% CI: 1.01 to 1.14; p = 0.017).
Conversely, when considering the entire follow-up period including the period after MV interventions, patients with a high RVol/EDV ratio (≥20%) had lower cumulative mortality event rates compared with those with a low RVol/EDV ratio (<20%): 5-year estimated rates 39.0% vs. 44.8% respectively; p = 0.018) (Figure 2B). The changes in HR across the range of RVol/EDV ratio (as a continuous variable) for all-cause mortality including MV interventions during follow-up are demonstrated as a fitted spline curve
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