Managing the Patient with Severe Left Ventricular Dysfunction



Managing the Patient with Severe Left Ventricular Dysfunction


Gregory W. Barsness



Along with the application of optimal medical and technological strategies to enhance prognosis, coronary anatomy and symptom status generally guide the clinical management of patients with severe left ventricular dysfunction. In patients with suitable coronary anatomy and evidence of ischemia, the decision to proceed with revascularization requires the evaluation and understanding of symptom status, comorbid conditions, availability of revascularization options, overall risk, and patient preferences. Even in the setting of continuing technical and medical advances, a significant association exists between poor left ventricular function (LVF) and poor outcome after coronary revascularization (1, 2, 3, 4). Although surgical revascularization may afford prognostic benefit among patients with a moderately depressed ejection fraction (5,6), it is increasingly the patient with debilitating angina and severely depressed ventricular function who presents for palliation.

Because of associated high procedural morbidity and mortality, patients with severe ventricular dysfunction may not be considered viable candidates for surgical intervention. Often, these patients have undergone previous surgical revascularization, as well, further complicating the issue of repeat revascularization (7). In these cases, percutaneous revascularization is an appropriate option and may provide the patient with both symptom relief and improved prognosis. Despite the emergence of alternative medical and invasive revascularization techniques, such as growth factor therapy, myocardial laser revascularization, and external counterpulsation, percutaneous coronary intervention (PCI) remains the preferred mechanical revascularization technique in the vast majority of patients with approachable lesions. This chapter reviews our approach to percutaneous revascularization in the high-risk patient with severe left ventricular dysfunction.


PATIENT SELECTION CHARACTERISTICS AND PREPARATION

The importance of sufficient preparation prior to high-risk coronary intervention cannot be overstated. This includes preparing the patient, as well as adequately addressing the procedural and technical concerns as an operator. Initial attention should be directed at determining the potential benefits and risks of any planned procedure. Prior to undertaking the procedure, discussion with the patient and family should include risks of the procedure and potential options. Due to the demonstrated prognostic benefits of complete revascularization with coronary bypass surgery in patients with depressed ventricular function (2,8,9), patients without significant comorbidities who are acceptable surgical candidates should generally be considered for bypass surgery (Table 40.1) unless all lesions can be approached percutaneously. Most patients with severe left ventricular dysfunction, however, are not candidates for surgical intervention, and percutaneous intervention is the mechanical revascularization procedure of choice (Table 40.2).

Several retrospective studies have failed to find a significant survival benefit associated with revascularization in
patients without demonstrable myocardial viability. Due to the inherent risk of intervention in patients with severe ventricular dysfunction, every effort should be made to identify areas of myocardial viability to assure that a successful intervention will provide the anticipated benefits of amelioration of ischemia and support of regional myocardial function (10). This is particularly true in the case of patients who are unable to undergo complete anatomic revascularization via the percutaneous approach. An identification of areas of ischemic burden may help to target specific ischemia-producing lesions among a host of potential candidates.








TABLE 40.1. OUTCOME OF FIRST CORONARY BYPASS GRAFTING PROCEDURE IN PATIENTS WITH SEVERE LV DYSFUNCTION: CONTEMPORARY SERIES

















































































































































































































































































































































Study (Reference)

Period

N

EF (%)

Primary Indication

Number of Grafts

30-Day Mortality (%)

1-Year Mortality (%)

Long-Term Mortality (%, Period)


Hausmann (33)

1986-92

265

24*

Elective/Angina

2.9

7.6

10.9

13.1 (3-year)


Kaul (34)

1987-92

210

≤20

Mix

–

8

18

27 (5-year)


Lindelow (35)

1988-92

7

24*

Elective/Ischemia ± MR

2-5

–

–

40 (3-year)#


Dreyfus (37)

1990-92

46

23*

Elective

3.8

10.9

13

–


Townend (38)

1991-92

15

20*

Elective/CHF

2.7

13

40†

–


Langenburg (39)

1983-93

96

20*

Elective

3.0

8

–

–


He (40)

1986-93

52

<30

Repeat CABG

–

33

–

–


Lee (41)

1986-93

35

25*

Elective/ICD**

2.7

3.7

–

29 (3-year)


Krucoff (42)

1990-93

21

<25

Elective

–

14

33

–


Christenson (43)

1990-93

91

21*

Mix/Angina

4.6

14.3

–

–


Calhoun (44)

1992-94

12

21*

Elective/CHF

–

17

–

–


Trachiotis (45)

1981-95

156

<25

Mix

3.3

3.8††

9.8

35.6 (5-year)
76.3 (10- year)


Elefteriades (26)

1986-95

135

≤30

(Semi)Elective/CHF

2.7

5.2

13

29 (4.5-year)


Dietl (46)

1991-95

163

22*

Mix

3.4

10

–

–


Salati (47)

1992-95

31

25*

Elective

2.6

0

–

–


Baumgartner (48)

1990-96

61

≤25

(Semi)Elective

4.0

8

–

–


Pagano (49)

1994-96

39

23*

Elective

3.0

5.7

14 (6-mo)

–


Mickleborough (50)

1982-97

125

<20

Mix

3.7

4††

–

28 (5-year)


Toda (51)

1992-97

69

25*

Elective

3.0

7

16

27 (3-year)


Bouchart (52)

1988-98

141

≤25

Elective/Angina

2.7

7

13

30 (5-year)


Carr (53)

1990-99

86

≤20

Mix

2.4

11

–

41 (5-year)


Antunes (54)

1990-99

141

<30

Elective

3.1

2.8

4

14 (5-year)


Kleikamp (55)

1988-2000

908

<30

Mix

3.1

1.98

–

11± (65-mo*)


AWESOME CABG Randomization (56,57)

1995-2000

47

<35

Elective

2.9##

–

–

28 (3-year)


AWESOME CABG Registry (57,58)

1995-2000

140

<35

Elective

–

–

–

40 (3-year)


Trehan (59)

1989-2001

176

<30

Elective

2.5

2.3††

–

–


S. Isbir (60)

1996-2001

212

<30

Elective/Urgent

3.2

5.6††

6

27 (4-year)


Goldstein On Pump (61)

1999-2001

110

≤30

Mix

3.5

10.9††

25

–


Goldstein OPCAB (61)

1999-2001

100

≤30

Mix

3.5

3††

15

–


Nishi (62)

1994-2002

42

24*

Elective

4.6

2.4

–

27 (5-year)


Ascione (63)

1996-2002

250

<30

Mix

2.7

4††

10

16 (3-year)


Al-Ruzzeh (64)

1999-2002

305

≤30

Elective/Urgent

2.9

11.5

–

–


* Mean.

** Patients received implantable cardiac defibrillator (ICD) implantation at the time of CABG.

† Includes one patient who underwent successful heart transplantation 8 months after CABG.

†† In-hospital events.

# Includes 5 patients who did not undergo combined valvular procedure.

## Overall cohort rate.

± Does not include 4.6% undergoing ventricular assist device placement or cardiac transplant during follow-up.


EF, ejection fraction; MR, mitral regurgitation; CHF, congestive heart failure; OPCAB, off pump coronary artery bypass grafting.


Although identification of ischemia is helpful in developing a revascularization strategy, the absence of ischemia or viability by noninvasive assessment does not exclude the potential benefit of revascularization. The extent of
viable but ischemic myocardium has been shown to determine the degree of improvement in LVF after surgical revascularization (11), but even positron emission tomography (PET), the gold standard for viability assessment, may underestimate the degree of myocardial recovery after revascularization. Between 10% and 20% of segments identified as nonviable by noninvasive imaging techniques demonstrate improved function after either CABG or percutaneous revascularization (12). Given this caveat, we use dobutamine echocardiography or PET imaging in the assessment of ischemia and viability, because these methods have reasonable sensitivity and specificity in identifying areas of viability and predicting subsequent improvement in regional wall motion after revascularization (13,14). Delayed contrast-enhanced cardiovascular magnetic resonance (DE-CMR) is another evolving technique that has shown promise in identifying reversible areas of myocardial dysfunction and is gaining prominence in viability assessment (15,16). It is important to note, however, that although a greater degree of demonstrable preoperative myocardial viability is associated with improved outcome after revascularization (17, 18, 19, 20, 21, 22, 23, 24), important prognostic
benefit may be afforded by revascularization even when regional myocardial function is not enhanced by revascularization efforts (25,26).








TABLE 40.2. RESULTS OF PERCUTANEOUS CORONARY INTERVENTION IN PATIENTS WITH SEVERE LV DYSFUNCTION: CONTEMPORARY SERIES

































































































































































































































































Study (Reference)

Period

N

EF (%)

Successful/Attempted Lesions (%)

Stent Use (%)

Major Complications (%)

In-Hospital MACE (%)

30-Day Mortality (%)

Late Mortality (%)


Unselected:


Maiello (65)

1987-91

100

30*

1.5/1.8 (83)

–

12

13

–

23#(19 mo*)


Krucoff (42)

1990-93

29

<25

–

–

–

–

10

45 (1 year)


Lindsay (66)

1995-96

194

<30

(93)

52

9.8

3.1

2.6##

16 (1 year)


Saucedo (67)

-1997**

85

<25

–

100

–

2.35

–

6.1 (1 year)


Toda (51)

1992-97

48

24*

-/1.5

67

–

–

8

27 (1 year)









33 (3 year)


Mayo (unpublished)

1994-97

392

29*

1.4/1.6 (88)

–

–

17

–

15 (1 year)


Bukachi (68)

1995-97

41

≤35

1.5/1.9 (83)

70

19.5

20

2.7

5.4 (1 year)


NHLBI Dynamic Registry (4)

1997-98

166

32*

1.4/1.5 (93)

74

–

6.6

3##

11 (1 year)


AWESOME PCI Randomization (56,57)

1995-2000

47

<35

–

54†

–

–

–

31 (3 year)


AWESOME PCI Registry (57,58)

1995-2000

152

<35

–

55†

–

–

–

37 (3 year)


Excimer Laser (69)

1997-2000

25

28*

1.1/1.2 (93)

83

8

0

–

–


Milan (70)

1998-2000

72

≤30

-/1.7

60

17

13

4##

–


Di Sciascio (71)

-2002**

8

28*

–

100

0

0

–

≥12 (3 year)


CPS Support:


Teirstein (72)

1989-90

126

≤20

1.6/1.8 (89)

–

41

8

–

–


Shawl (73)

1988-91

107

19*

1.8/1.9 (95)

0

0

4.7

–

23 (2 year)


Beaumont (74)

-1997***

58

26*

(99)

–

–

–

12##

–


IABP Support:


Kreidieh (75)

1987-91

16

<30

-/1.6

–

6

12

–

6 (1 year)


Beaumont (74)

-1997***

91

32*

(87)

–

–

–

8.7

–


Milan Elective IABP (70)

1998-2000

61

≤30

-/2.0

72

5

5

2##

–


Supported:


Ferrari (76)

1990-93

35

30*

1.7/2.0 (85)

–

17

–

8.6##

23 (1 year)
30 (2 year)


* Mean.

** Submission year.

*** 4-year study published 1998.

# Includes 9% in-hospital mortality plus follow-up mortality in 75 patients with clinically successful initial procedures.

## In-hospital mortality.

† Overall cohort rate.


EF, ejection fraction; MACE, major adverse cardiac events, including death, myocardial infarction, and repeat revascularization; CPS, cardiopulmonary support; IABP, intra-aortic balloon pump.

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Sep 23, 2016 | Posted by in CARDIOLOGY | Comments Off on Managing the Patient with Severe Left Ventricular Dysfunction

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