**11. Controversial Topics**

In a multi-variate analysis of the clinical characteristics, the following variables were found

Of all of the variables, the strongest predictor of a poor outcome was pre-operative renal failure requiring dialysis. Interestingly, favorable variables included a history of hyperten‐ sion, congestive heart failure, and need for concomitant CABG. The authors emphasized pa‐ tients, due to their physiologic status, who required earlier intervention tended to have worse outcome. Obviously, the controversies regarding the balance between the timing of

Unfortunately, there is little data reporting long-term survival. In their report of 68 patients undergoing surgery for PI-VSD between 1988 and 2007, Fukushima and colleagues from Brisbane, Australia provide some valuable insight and predictors of long-term outcomes [21]. In their report, 85% of patients underwent urgent surgery within 48 hours of diagnosis, 71% had concomitant CABG, and 30-day mortality was 35%. The mean follow-up was 9.2 years. Overall short-time outcomes and predictors of survival were similar to previous re‐ ports (as discussed above). The actuarial survival at 1 year was 67%, 63% at five years, 51% at 10 years, and 36% at 15 years. However, freedom from main adverse coronary events of the survivors was 91%, 61%, 40%, and 19% at 30 days, 1 year, 5 years, and 15 years respec‐ tively. At 5 years, freedom from congestive heart failure was 70% and 85% for ventricular arrhythmias – while at 10 years, 54% were free of heart failure and 71% from arrhythmias. For the cumulative survival analysis, there were 43 patients alive a 1 year, 34 at 5 years, 22 at

to be predictors of post-operative death:

**1.** Advancing age (>65 years/old)

312 Principles and Practice of Cardiothoracic Surgery

**4.** Pre-operative cardiogenic shock

**6.** Peripheral vascular disease

**8.** Re-do cardiac surgery

**10.** Pre-operative dialysis

10 years, and 6 at 15 years.

**9.** Emergent/Salvage surgery

**11.** Pre-operative mitral regurgitation

intervention and clinical optimization continue.

**5.** Pre-operative need for intra-aortic balloon pump

**7.** Percutaneous coronary intervention within 6 hours of surgery

**2.** Lower Ejection Fraction

**3.** Female (vs. male)

#### **11.1. Percutaneous Closure devices**

Successful application of less invasive non-surgical options and closure devices in children with congenital VSDs has prompted enthusiasm for the use of similar closure devices in pa‐ tients with PI-VSDs. The role of such devices has been proposed for both the primary clo‐ sure of acute defects and to assist in the closure of recurrent or residual shunts [41].

However, because of the appeal of a less-invasive, non-surgical, option for these critically ill patients, investigators continue to try and define the role of septal occluder devices in pa‐ tients with PI-VSDs. Attia recently reviewed the literature of such devices [5]. Thirty manu‐ scripts were reviewed, but only 5 studies, consisting of approximately 100 patients, were felt to provide some insight into a "best practice" recommendation – despite numerous case re‐ ports. The general recommendations were that 1) surgical management still should be con‐ sidered the 'gold standard' for patients with PI-VSDs but occluder devices might have a role in small defects (< 15 mm diameter) and in patients who present late (> 3.5 weeks after the index event). Attia also suggested a potential role in attempting to minimize a significant shunt in patients who are too ill to survive surgery as temporizing and potential means of stabilizing a patient prior to urgent surgical intervention.

While conceptually promising, the complex nature of acute defects as compared to congeni‐ tal defects has tempered some of the early enthusiasm as early experiences were discourag‐ ing and improvements in outcomes were not observed [35]. Difficulties in covering not only the actual defect, but also the residual necrotic myocardium predisposed to early recurrence. Challenges remain in the technology because of problems positioning the devices and ade‐ quately covering potentially complex defects.

#### **11.2. Mechanical Support**

Despite advances in surgical and post-operative management, operative mortality is still high and depending on clinical presentation can vary between 10-60%[14]. Even with early inter‐ vention, biventricular failure is often a significant factor in early post-operative deaths. Short and long-term mechanical support, beyond intra-aortic balloon counterpulsation, is a reason‐ able option in patients with post-operative ventricular (left, right, or bi) failure and who are felt to be salvageable. Short-term support may be required as a bridge to recovery, while longterm device therapy may be indicated for those with irreversible ventricular failure. Since early acute co-morbidities and associated cardiogenic shock predict poor outcomes, there is some evidence and support for pre-operative biventricular mechanical support to allow for clini‐ cal optimization and stabilization as a bridge to definitive repair [11].

In cases in which there is extensive ventricular infarction and acute heart failure, associat‐ ed free-wall rupture, or when there is excessive bleeding or tension from the ventriculoto‐ my, temporary left ventricular support should be considered. With LVAD inflow drainage from the left atrium, the LV is unloaded (i.e. 'atrialized') and may allow time as a bridge to recovery before exposing the compromized left ventricle to systemic pressures and con‐ tractile function [19].

**12. Conclusions**

**13. Conflicts of Interest**

**Acknowledgements**

**Author details**

nologies discussed in this manuscript.

from InTech for use of copyrighted images [20].

Michael S. Firstenberg1\*, Kevin T. Kissling2

1 Division of Cardiac Surgery, U. S. A.

\*Address all correspondence to: Michael.Firstenberg@osumc.edu

2 Department of Pharmacy, The Ohio State University Medical Center, U. S. A.

Ventricular septal defects after acute myocardial infarction are rare events. With modern re‐ perfusion strategies, septal defects occur in up to 0.02% of acute myocardial infarctions. De‐ spite advances and experiences in the management of these complex patients, operative mortality still approaches 50% with major risks including cardiogenic shock, renal failure, right and/or left ventricular failure, size of the defect with degree of shunting, posterior/infe‐ rior locations, and residual post-repair shunting. While some patients may present late or benefit from watchful waiting and a delayed repair, typically surgical intervention is indi‐ cated prior to irreversible end-organ damage. Repair techniques emphasize closure of the defect and protecting the injured septum from left ventricular pressures while avoiding ad‐ ditional injury to the already compromised left and right ventricles. Post-operative manage‐ ment is typically challenging considering the inherent pre-operative biventricular dysfunction and often encountered end-organ dysfunction. Those who survive their initial

Management And Controversies of Post Myocardial Infarction Ventricular Septal Defects

http://dx.doi.org/10.5772/53396

315

The authors have no conflicts of interest or disclosures related to any of the topics or tech‐

This chapter, figures, and tables were adopted from a previous version with permission

and Karen Nelson1

event and operation tend to have favorable 5 and 10-year survivals.

Right ventricular mechanical support is also difficult following the acute volume/pressure overload of a PI-VSD with recovery unpredictable and potentially prolonged. Unfortunate‐ ly, there is little data to guide decision making other than clinical judgment and center expe‐ rience with management of acute post-cardiotomy right heart failure.

Residual shunts after repair pose a unique challenge for patients requiring mechanical sup‐ port. Careful attention to left and right ventricular flows and pressures are critical to com‐ pensate for the residual shunt – and prevent worsening of over-circulation [39]. If residual shunts are significant then biventricular support, either with long-term ventricular assist de‐ vices or extra-corporeal membrane oxygenation, may allow for a period of recovery and sta‐ bilization prior to an attempted repair in an otherwise very high-risk surgical patient [44]. The decision to intervene surgically on residual shunts, because of the extremely high opera‐ tive mortality as discussed above, must clearly be made in the context of the overall clinical condition of the patient. Small defects can be managed medically and can be surprisingly well tolerated physiologically for years.

The need for mechanical support, while attractive in unstable post-operative patients, is also not without substantial risks. Often there is need for aggressive anti-coagulation, multiple surgical procedures (i.e. device change-outs, explants, re-operation for bleeding, etc), and overall patient recovery is more difficult when tethered to external VAD controllers. In addi‐ tion, the risks for infectious complications with long-term support are considerable.

A total artificial heart, by definition, eliminates native cardiac recovery and mandates car‐ diac transplantation, nevertheless, it may be an option with appropriate resources and expe‐ rience in highly selected patient with few other comorbidities and in general, is probably a poor idea.

#### **11.3. Residual/Recurrent Defects**

Residual shunts are found in up to 25% of patients after definitive repair [43]. The etiology of residual shunts is either a missed defect at the time of initial repair, dehiscence of a patch (sewn to necrotic or friable tissue), or further extension of the initial defect. Fortunately, most residual shunts tend to be physiologically tolerated and spontaneous closure has been reported. Operative re-intervention is associated with a >60% mortality [27] and surgery is reserved for patients in heart failure failing medical management or those with large shunts (Qp:Qs>2.0) [34]. Because of the high operative mortality with repairing residual or recur‐ rent shunts there has been interest, but limited success, with percutaneous closure devices [41]. Nevertheless, the role of percutaneous closure and the ideal devices are undefined [35] and probably best reserved for use in those centers with extensive experience in the closure of congenital VSDs.
