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Failure of aneurysmectomy to improve left ventricular function
Insights
Aneurysmectomy for left anterior descending artery disease with anterior aneurysm does not improve heart function. Reducing heart chamber volumes is offset by damage to the transitional section, hindering recovery.
Area of Science:
- Cardiology
- Cardiac Surgery
- Cardiovascular Imaging
Background:
- Anterior aneurysms following myocardial infarction can impair left ventricular function.
- Surgical intervention aims to improve cardiac performance by removing dysfunctional tissue.
Purpose of the Study:
- To evaluate the impact of aneurysmectomy on left ventricular function in patients with isolated left anterior descending artery disease and anterior aneurysm.
- To investigate the relationship between myocardial tissue characteristics and overall ventricular performance post-surgery.
Main Methods:
- Biplane left ventricular angiography in 22 patients with anterior aneurysm.
- Assessment of left ventricular reserve using postextrasystolic beats.
- Histological examination of excised aneurysm and transitional myocardial sections.
- Pre- and post-aneurysmectomy functional analysis.
Main Results:
- Increased noncontractile and transitional sections correlated with larger end-diastolic and end-systolic volumes and reduced ejection fraction.
- Aneurysmectomy significantly reduced end-diastolic and end-systolic volumes but did not improve ejection fraction.
- Surgical resection of the transitional section resulted in akinetic areas, negating volume reduction benefits.
Conclusions:
- Aneurysmectomy in this specific patient group fails to enhance left ventricular function.
- The destruction of contractile behavior in the transitional myocardial section offsets the benefits of reduced ventricular volumes.
- Myocardial viability and function within the transitional zone are critical factors in post-surgical outcomes.
Abstract:
Biplane left ventricular angiography was performed in 22 patients with isolated obstructive disease of the anterior descending branch of the left coronary artery and with an anterior aneurysm following transmural myocardial infarction. Six patients were restudied between 6 and 10 months after aneurysmectomy. Left ventricular reserve was estimated by analysis of a spontaneous postextrasystolic beat. Using angiographic techniques a contractile section, a transitional section, and a noncontractile section were identified. From the surgical patients the excised aneurysm and a transmural needle biopsy of the transitional section were investigated by light microscopy. With increasing volumes of noncontractile and transitional sections, total end-diastolic volume (r = 0.81, P less than 0.001) and end-systolic volume (r = 0.94, P less than 0.001) increased linearly, while the ejection fraction decreased (r = 0.70, P less than 0.001). No relation was found between the combined volumes of the noncontractile and transitional sections on the one hand, and the end-diastolic volume, the end-systolic volume, or the ejection fraction of the contractile section on the other hand. After aneurysmectomy a significant decrease was found in end-diastolic volume (194 to 133 ml/m2, P less than 0.001) and end-systolic volume (124 to 83 ml/m2, P less than 0.001) but no change occurred in ejection fraction (35 to 37%) and left ventricular end-diastolic pressure (23 to 25 mmHg). Surgical resection included part of the transitional section, which before surgery had an average ejection fraction of 27 per cent during a normal beat, rising to 41 per cent in a postextrasystolic beat. The transitional section after surgery now formed a large akinetic area of the anterior wall. We conclude that aneurysmectomy in isolated left anterior descending artery disease with anterior aneurysm fails to improve left ventricular function because the effect of reduction of left ventricular volumes is offset by the destruction of contractile behaviour in the transitional section.