Introduction: Ventricular-arterial coupling (VAC) is defined as the ratio between the arterial elastance and the end-systolic ventricular elastance and it reflects the efficiency of the energy transfer from the left ventricle to the aorta. Noninvasive assessment of VAC can be derived from a routine echocardiogram. Its prognostic role was studied in different clinical scenarios and the ventricular-vascular uncoupling was associated with poor clinical outcomes and suboptimal response to therapy. Information regarding the changes of VAC in patients with acute heart failure and preserved ejection fraction (EF) has been scarce so far.
Objective: To assess the VAC in a cohort of patients with acute pulmonary edema and preserved EF and compare it with a normal reference group.
Methods: We included 50 consecutive patients with acute pulmonary edema and preserved EF in our study. Patients with severe aortic or mitral valve disease were not considered eligible. Neither of the patients had an-gina on admission, nor did they have previous histo-ry of ischemic heart disease. We performed thorough echocardiographic evaluation on admission for these patients and we assessed the VAC non-invasively, as the ratio between the arterial elastance and the ventricular elastance. The control group consisted of 50 subjects with no heart disease. We used T-test to compare para-meters between the two groups.
Results: The mean age in the study group was 76±12.14 years, while the mean age in the control group was 40±13.38 years (p <0.0001). Both groups had preserved EF: the mean EF was 55.2%±7.2% in the study group and 54.8%±5.1% in the control group (p=0.72). The blood pressure (BP) on admission was higher in the acute pulmonary edema group: 180.9±39.8 mm Hg, versus 122.2±13.8 mm Hg in the control group for the systolic BP (p<0.0001) and 94.1±24.8 mm Hg, versus 73.8±10.6 mm Hg in the control group for the diasto-lic BP (p<0.0001). The arterial elastance was higher in the acute pulmonary edema group: 2.65±1.19, versus 1.50±0.35 in the normal group (p<0.0001). The ventri-cular elastance was also higher in the acute pulmonary edema group: 3.98±1.98, versus 1.93±0.66 in the nor-mal group (p<0.0001). However, the non-invasive VAC was significantly lower in the acute pulmonary edema group: 0.6916±0.168 versus 0.806±0.139 in the normal group (p=0.0003).
Conclusions: VAC provides us with a better under-standing of the ventricular and vascular mechanics and with a pathophysiological insight of acute pulmonary edema in patients with preserved EF. This parameter should be routinely analyzed in such patients, since it is derived from simple echocardiographic measurements. Impaired VAC may serve as a base for intensive cardi-ovascular prevention or even tailored therapy in pati-ents with cardiovascular risk factors, while in patients with acute pulmonary edema and preserved EF, it mi-ght unravel potential therapeutic targets and thus gui-de the therapeutic strategy, should it be studied more extensively.