Regression in left ventricular mass after aortic valve replacement for chronic aortic regurgitation is unrelated to prosthetic valve size

Patient-prosthesis mismatch in patients with aortic valve replacement

OBJECTIVE

Patient-prosthesis mismatch (PPM) may affect clinical outcomes in patients with aortic valve replacement (AVR). We retrospectively examined the PPM in patients with isolated AVR in the Japan Adult Cardiovascular Surgery Database (JACVSD).

METHODS

We examined all patients with isolated AVR between January 1, 2008 and December 31, 2009. The JACVSD data collection form has a total of 255 variables. We defined PPM as an effective orifice area index of ≤ 0.85 m(2)/cm(2).

RESULTS

PPM was observed in 306 of 3,609 cases analyzed, PPM rate was 8.5 %. Body surface area was larger and body mass index was higher in the PPM group than the non-PPM group (P < 0.001). Patients with PPM were older (P = 0.001) and had a higher prevalence of diabetes (P = 0.004), dyslipidemia (P < 0.001), hypertension (P < 0.001), cerebrovascular disease (P = 0.031), old myocardial infarction (P = 0.006), previous percutaneous coronary artery intervention (P = 0.001), coronary artery disease (P = 0.018), and aortic valve stenosis (P < 0.001). Perioperative blood transfusion (P < 0.001) and dialysis (P = 0.005) were more frequent in the PPM group. Postoperative ventilation (P = 0.004) and intensive care unit stay (P = 0.004) were significantly longer in the PPM group.

CONCLUSIONS

Age, aortic valve stenosis, dyslipidemia, hypertension, old myocardial infarction, previous percutaneous coronary artery intervention, diabetes mellitus, cerebrovascular disease, and high body mass index were the risk factors for PPM. PPM was not an independent risk factor for short-term mortality.

Valve prosthesis-patient mismatch (VP-PM): a long-term perspective

The concept/phenomenon of valve prosthesis/patient mismatch (VP-PM), described in 1978, has stood the test of time. From that time to 2011, VP-PM has received a great deal of attention but studies have come to varying conclusions. This is largely because of the determination of prosthetic heart valve area [called effective orifice area index (EOAi)] by projection rather than by actual measurement, variable criteria to assess severity of EOAi and the timing of determination of EOAi. All prosthetic heart valves have some degree of VP-PM which must be placed in a proper clinical perspective. This can be done by determining its effects on function and outcomes. For mortality one needs to focus especially on severe/critical degree of VP-PM and determine the cause of death was due to VP-PM. For the period "beyond 2011" a road map is suggested that will have uniformity of assessment of VP-PM and a focusing on the important goals of VP-PM.

Magnetic resonance imaging versus echocardiography to ascertain the regression of left ventricular hypertrophy after bioprosthetic aortic valve replacement: results of the REST study

OBJECTIVES

To compare the decrease in left ventricular mass index (LVMI) by magnetic resonance imaging (MRI) versus transthoracic echocardiography (TTE) after aortic valve replacement (AVR) for severe aortic stenosis with Epic and Epic Supra stented porcine bioprostheses (St Jude Medical, Inc, St Paul, Minn).

METHODS

This prospective multicenter study enrolled 149 patients who underwent AVR between January 2006 and February 2008. TTE and cardiac MRI measurements of LVMI were made at baseline and at 6 months of follow-up and were compared. Changes in mean pressure gradients were examined using TTE.

RESULTS

TTE measurements of LVMI were 48% to 63% higher than the MRI measurements. A decrease in LVMI from 137 ± 32 to 95 ± 16 g/m(2) with the Epic and from 139 ± 29 to 104 ± 28 g/m(2) with the Epic Supra valves (P < .0001 for both comparisons) was measured by TTE. Cardiac MRI revealed decreases in LVMI from 84 ± 20 to 64 ± 12 g/m(2) and from 86 ± 27 to 64 ± 17 g/m(2) with the Epic and Epic Supra valves, respectively (P < .0001 for both comparisons). TTE revealed a significant regression of mean pressure gradients from 51.6 ± 15.3 to 15.5 ± 5.2 mm Hg with the Epic and from 46.7 ± 19.4 to 17.9 ± 12.8 mm Hg with the Epic supra (P < .0001 for both comparisons).

CONCLUSIONS

A significant decrease in LVMI was measured after AVR with all sizes of both bioprosthetic models. Because of the overestimation of the decrease in LVMI by the Devereux formula, as well as the higher accuracy and reproducibility of cardiac MRI measurements, the latter should be preferred to TTE. An ultimate validation of this thesis could only be done comparing each of these modalities with pathologic examination.