Where is the output in the LSTM?
Usually you have to add a Dense layer after the LSTM unit. That will try to understand how to use the output of LSTM.

For example in Keras:

model = Sequential()
model.add(LSTM(4, input_shape=(1, 5)))
model.add(Dense(1, activation='sigmoid'))
model.compile(loss='binary_crossentropy', optimizer='adam')