4. ischemic heart disease (coronary artery disease)

Q: What is ischemic heart disease?

The disease develops by having narrowed or occluded coronary arteries (Figure) by atherosclerosis.  As life style becomes westernized, the ischemic heart disease is now one of the number 1 killers.

The best way to solve the problem is to prevent the disease by controlling risk factors (i.e., causes of the disease such as Diabetes Mellitus, Hypertension, Smoking, Hyperlipidemia, Family History or Metablic sydrome which draws public attention).

As ischemic heart disease progresses, however, treatment becomes necessary, since the disease is often fatal.  Initial treatment consists of conservative or medical treatment such as proper dieting, excercise, or medication or catheter treatment (balloon or stent). If the disease become beyond the medical treatment, surgery is necessary.

Patients with chronic renal failure or hemodialysis have rapid progress of the ischemic heart disese, and they should be careful.

Q: What type of surgery is there for angina pectoris?

Surgery for angina pectoris (squeezing pain of chest or inner arm) consists of coronary artery bypass grafting (CABG).

In the CABG, internal thoracic artery (ITA), gastroepiploic artery in the upper belly, radial artery in the forearm, or saphenous vein in the legs.  By combining the grafts, we make a bypass for coronary arteries to supply blood (i.e., oxygen or nutrition).

  As internal medicine makes progress, now drug-elluting stents (DES) are available and popular. CABG, however, still offers many benefits for patients.

In the recent 10 years, CABG has evolved to off-pump CABG (OPCAB) which does not require cardiopulmonary bypass. OPCAB offers even safer surgery.

ITA grafts which are usually employed in the CABG/OPCAB surgery are resistant to atherosclerosis, and makes excellent grafts for patients with diabetes mellitus or chronic renal failure/hemodialysis and is known to improve their long term survival.

In our experiences, ITAs keeps soft and excellent conditions even in patients who had more than 10 years hemodialysis and who had badly calcified coronary arteries.

Q: Is drug eluting stents (DES) almighty?

DES (left picture, anti-cancer drug is coated on the surface to prevent growth of intimal cells) requires patients to take anti-platelet medications for long time. Otherwise they may die suddenly of coronary thrombosis. Patients who had DES may not become as healthy as expected.

In Europe or America, DES are reported to carry higher risk in long-term survival than conventional stents, and DES dream has been broken. Moreover, DES patients who had stomack or lung cancer diagnosed later had a problem of having surgery, because they could not stop taking anti-platelet medications which is obstacle for cancer surgery.

CABG patients usually do not need as strong medications as DES, and they have no problem of cancer or trauma surgery when necessary in the future.  We believe that DES and CABG should be chosen according to patients' situation and needs.

Q: How safe is CABG surgery?

Our results of CABG shows hospital mortality of less than 1%. 

We achieve the results even by doing surgery for patients over 90 years-old, or sick patients with various disease such as chronic renal failure/hemodiaslysis or COPD or post-stroke, or patients who need emergency surgery etc., if they are properly indicated.  We do not give up surgery for sick patients when they have indication for surgery.

However, patients population has changed. In the past decade, we had a record of zero-mortality for 7 years in    CABG surgery. More recently, we lost a couple of patients because they were indicated not for conventional treatment but for regenerative medicine (tissure engineering), and therefore very sick. One patient was not indicated even for regenerative medicine. On the other hands, other patients with usual condition keeps zero mortality.

In CABG, safety is maintained even in patients with chronic renal failure or hemodialysis.

We experienced CABG in a patient who had over 30 years of hemodialysis.

His coronary arteries were as calcified as lead-pipe. His ITAs, however, were soft and excellent for grafting the diseased coronary arteries (left picture).

  In the operation, we examined the anastomosis by using high-speed echocardiography (picture below);

calcified coronary artery with high echo-signal and relatively normal ITA are shown.

Reasons of low mortality of CABG are:

1. surgery by experienced and professional team

2. Off-pump CABG (OPCAB) which is free from complications of cardiopulmonary bypass (OPCAB Case)

3. Safe management/treatment before, during and after the surgery

In Nagoya Heart Center/Toyohashi Heart Center and Yamato Seiwa Hospital, in additon to the above 2., 1. and 3. are reinforced which makes very safe treatment. Those hospitals are dedicated to the treatment of heart disease and are ideal place to do it.

Q: Off-pump CABG is not suitable for buried (intramuscular) coronary arteries, correct?

The answer is "Not necessarily".

When necessary, we have methods to find, capture, and handle the intramuscular coronary arteries.

We use both experience and high-speed echocardiography and surely find the intramuscular coronary arteries.

The above left picture shows the deep intramuscular coronary artery, the above middle picture the moment when we exposed the artery, and the above right picture shows the way to "dig" the artery.

Q: Can surgery be indicated when angina gets worse to myocardial infarction?

So far, it is difficult to recover the lost myocardium by myocardial infarction. In the future, regenerative medicine will enable the recovery, but at the moment, it is difficult. We can improve the power of the heart by fully utilizing the remaining myocardium.

For example, LV restoration surgery helps patients with LV aneurysm where infarcted LV wall becomes bulge, and patients with ischemic cardiomyopathy where whole LV motion is impaired.

In LVR, diseased part of the LV wall is excised and sutured, which makes the residual intact part of the LV wall more vigorous and powerful.

We have experiences of LVR in more than 100 patients, and most of them except for those who had had multi-organ failure before the surgery were cured and doing well.

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Q: What kind of LV restoration surgery are there for ischemic cardiomyopathy? Is pacemaker useful for those patients ?

  We do surgery for those who have severe heart failure by using: Dor surgery (IHD Case 2), SAVE surgery which is more geometric than Dor surgery for some patients (IHD Case 3), and modified Batista surgery (we modified the Batista surgery by preserving the LV apex).

The methods are improving the surgical results. (Please see the pages of cardiomyopathy or heart failyre)

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  Moreover, in addition to the LVR, biventricular pacing (CRT, chronic resynchronization therapy) (left figure) further improves LV function and results of the surgery (IHD Case 4).

  So far, many patients who had been "given-up" and told to be a transplant candidate in other hospitals were saved by the above LVR surgery. (Please note that donor hearts are seldom available in this country.)

We select SAVE surgery or modified Batista surgery depending on the LV site to be repaired (i.e., SAVE for interventricular septum and Batista for LV free wall). If there is an indication, we do LVR for patients on their 80s with minimum mortality (IHD Case 5).

We sometimes do Overlap surgery (IHD Case 6). The surgery has several merits but has some potential problems such as no volume-reduction effects for LV base and leaving diseased LV wall which may lead to future re-remodeling (i.e., re-dilation). We confirmed it in animal experiments. Thus we do not employ the Overlap surgery in a routine fashion.

In LVR surgery, we often visit other hospitals for operation when the hospital is too distant or when the patient is too sick to come to us.

Q: Ischemic mitral regurgitation (IMR) secondary to myocardial infarction is hard to repair, correct?

  Patients with Ischemic MR (left figure) do not always recover well after simple CABG surgery, and they often come back to the hospital with recurrent heart failure. Their long term results are not necessarily impressing.

We kept working on the surgery for ischemic MR and improving the results.

Ischemic MR is not a "valvular disease" but a "ventricular disease" in its nature; in other words, ischemic MR is caused by distortion and dilation of the LV by myocardial infarction or ischemia. Thus we try to repair not only the valve but also LV.

For details, please see the section of 2. mitral valve disease and atrial fibrillation in the valvlar heart disease in this home page.

Q: Is the ruptured septum or LV after the myocardial infarction repairable?

Blow-out type

We developed a surgical method to repair the LV with blow-out rupture (i.e., blood spraying from the LV tear).

The key concept of the method is to stop/confine myocardial dissection from outside of the LV to minimize the invasiveness for the patient.

We employed the method for 5 patients with very good results.

In more gentle rupture (Oozing type LV rupture), we apply surgical glue sheet on the ruptured LV site and the site around. Bleeding usually stops by the method.

Ventricular septal rupture (VSP) or post-infarction VSD

In the treatment of VSP, infarction exclusion technique that we developed in Toronto in late 1980s is employed (IHD Case 7). The method decreased the operative mortality from 30% to 10% at that time.  We keep improving the method to improve the results furthermore.

Currently we modify the patch material and its shape, avoid GRF glue which is toxic, and employ 2 patch method which has check-valve function and is suitable to protect the infarcted LV site.

We see more elderly and sick patients with VSP, and further efforts are necessary and expected.

In the treatment of VSP, team-work and inter-hospital cooperation is more important than usual. We discuss with doctors in cardiology and general medicine so that the VSP patients can be referred to the hospital on earlier occasion.